test_trace.py

# -*- coding: utf-8 -*-
from __future__ import (absolute_import, division, print_function,
                        unicode_literals)
from future.builtins import *  # NOQA

import math
import os
import unittest
from copy import deepcopy
import warnings

import numpy as np
import numpy.ma as ma

from obspy import Stream, Trace, UTCDateTime, __version__, read, read_inventory
from obspy.core import Stats
from obspy.core.compatibility import mock
from obspy.core.util.testing import ImageComparison
from obspy.io.xseed import Parser


class TraceTestCase(unittest.TestCase):
    """
    Test suite for obspy.core.trace.Trace.
    """
    @staticmethod
    def __remove_processing(tr):
        """
        Removes all processing information in the trace object.

        Useful for testing.
        """
        if "processing" not in tr.stats:
            return
        del tr.stats.processing

    def test_init(self):
        """
        Tests the __init__ method of the Trace class.
        """
        # NumPy ndarray
        tr = Trace(data=np.arange(4))
        self.assertEqual(len(tr), 4)
        # NumPy masked array
        data = np.ma.array([0, 1, 2, 3], mask=[True, True, False, False])
        tr = Trace(data=data)
        self.assertEqual(len(tr), 4)
        # other data types will raise
        self.assertRaises(ValueError, Trace, data=[0, 1, 2, 3])
        self.assertRaises(ValueError, Trace, data=(0, 1, 2, 3))
        self.assertRaises(ValueError, Trace, data='1234')

    def test_setattr(self):
        """
        Tests the __setattr__ method of the Trace class.
        """
        # NumPy ndarray
        tr = Trace()
        tr.data = np.arange(4)
        self.assertEqual(len(tr), 4)
        # NumPy masked array
        tr = Trace()
        tr.data = np.ma.array([0, 1, 2, 3], mask=[True, True, False, False])
        self.assertEqual(len(tr), 4)
        # other data types will raise
        tr = Trace()
        self.assertRaises(ValueError, tr.__setattr__, 'data', [0, 1, 2, 3])
        self.assertRaises(ValueError, tr.__setattr__, 'data', (0, 1, 2, 3))
        self.assertRaises(ValueError, tr.__setattr__, 'data', '1234')

    def test_len(self):
        """
        Tests the __len__ and count methods of the Trace class.
        """
        trace = Trace(data=np.arange(1000))
        self.assertEqual(len(trace), 1000)
        self.assertEqual(trace.count(), 1000)

    def test_mul(self):
        """
        Tests the __mul__ method of the Trace class.
        """
        tr = Trace(data=np.arange(10))
        st = tr * 5
        self.assertEqual(len(st), 5)
        # you may only multiply using an integer
        self.assertRaises(TypeError, tr.__mul__, 2.5)
        self.assertRaises(TypeError, tr.__mul__, '1234')

    def test_div(self):
        """
        Tests the __div__ method of the Trace class.
        """
        tr = Trace(data=np.arange(1000))
        st = tr / 5
        self.assertEqual(len(st), 5)
        self.assertEqual(len(st[0]), 200)
        # you may only multiply using an integer
        self.assertRaises(TypeError, tr.__div__, 2.5)
        self.assertRaises(TypeError, tr.__div__, '1234')

    def test_ltrim(self):
        """
        Tests the ltrim method of the Trace class.
        """
        # set up
        trace = Trace(data=np.arange(1000))
        start = UTCDateTime(2000, 1, 1, 0, 0, 0, 0)
        trace.stats.starttime = start
        trace.stats.sampling_rate = 200.0
        end = UTCDateTime(2000, 1, 1, 0, 0, 4, 995000)
        # verify
        trace.verify()
        # UTCDateTime/int/float required
        self.assertRaises(TypeError, trace._ltrim, '1234')
        self.assertRaises(TypeError, trace._ltrim, [1, 2, 3, 4])
        # ltrim 100 samples
        tr = deepcopy(trace)
        tr._ltrim(0.5)
        tr.verify()
        np.testing.assert_array_equal(tr.data[0:5],
                                      np.array([100, 101, 102, 103, 104]))
        self.assertEqual(len(tr.data), 900)
        self.assertEqual(tr.stats.npts, 900)
        self.assertEqual(tr.stats.sampling_rate, 200.0)
        self.assertEqual(tr.stats.starttime, start + 0.5)
        self.assertEqual(tr.stats.endtime, end)
        # ltrim 202 samples
        tr = deepcopy(trace)
        tr._ltrim(1.010)
        tr.verify()
        np.testing.assert_array_equal(tr.data[0:5],
                                      np.array([202, 203, 204, 205, 206]))
        self.assertEqual(len(tr.data), 798)
        self.assertEqual(tr.stats.npts, 798)
        self.assertEqual(tr.stats.sampling_rate, 200.0)
        self.assertEqual(tr.stats.starttime, start + 1.010)
        self.assertEqual(tr.stats.endtime, end)
        # ltrim to UTCDateTime
        tr = deepcopy(trace)
        tr._ltrim(UTCDateTime(2000, 1, 1, 0, 0, 1, 10000))
        tr.verify()
        np.testing.assert_array_equal(tr.data[0:5],
                                      np.array([202, 203, 204, 205, 206]))
        self.assertEqual(len(tr.data), 798)
        self.assertEqual(tr.stats.npts, 798)
        self.assertEqual(tr.stats.sampling_rate, 200.0)
        self.assertEqual(tr.stats.starttime, start + 1.010)
        self.assertEqual(tr.stats.endtime, end)
        # some sanity checks
        # negative start time as datetime
        tr = deepcopy(trace)
        tr._ltrim(start - 1, pad=True)
        tr.verify()
        self.assertEqual(tr.stats.starttime, start - 1)
        np.testing.assert_array_equal(trace.data, tr.data[200:])
        self.assertEqual(tr.stats.endtime, trace.stats.endtime)
        # negative start time as integer
        tr = deepcopy(trace)
        tr._ltrim(-100, pad=True)
        tr.verify()
        self.assertEqual(tr.stats.starttime, start - 100)
        delta = 100 * trace.stats.sampling_rate
        np.testing.assert_array_equal(trace.data, tr.data[int(delta):])
        self.assertEqual(tr.stats.endtime, trace.stats.endtime)
        # start time > end time
        tr = deepcopy(trace)
        tr._ltrim(trace.stats.endtime + 100)
        tr.verify()
        self.assertEqual(tr.stats.starttime,
                         trace.stats.endtime + 100)
        np.testing.assert_array_equal(tr.data, np.empty(0))
        self.assertEqual(tr.stats.endtime, tr.stats.starttime)
        # start time == end time
        tr = deepcopy(trace)
        tr._ltrim(5)
        tr.verify()
        self.assertEqual(tr.stats.starttime,
                         trace.stats.starttime + 5)
        np.testing.assert_array_equal(tr.data, np.empty(0))
        self.assertEqual(tr.stats.endtime, tr.stats.starttime)
        # start time == end time
        tr = deepcopy(trace)
        tr._ltrim(5.1)
        tr.verify()
        self.assertEqual(tr.stats.starttime,
                         trace.stats.starttime + 5.1)
        np.testing.assert_array_equal(tr.data, np.empty(0))
        self.assertEqual(tr.stats.endtime, tr.stats.starttime)

    def test_rtrim(self):
        """
        Tests the rtrim method of the Trace class.
        """
        # set up
        trace = Trace(data=np.arange(1000))
        start = UTCDateTime(2000, 1, 1, 0, 0, 0, 0)
        trace.stats.starttime = start
        trace.stats.sampling_rate = 200.0
        end = UTCDateTime(2000, 1, 1, 0, 0, 4, 995000)
        trace.verify()
        # UTCDateTime/int/float required
        self.assertRaises(TypeError, trace._rtrim, '1234')
        self.assertRaises(TypeError, trace._rtrim, [1, 2, 3, 4])
        # rtrim 100 samples
        tr = deepcopy(trace)
        tr._rtrim(0.5)
        tr.verify()
        np.testing.assert_array_equal(tr.data[-5:],
                                      np.array([895, 896, 897, 898, 899]))
        self.assertEqual(len(tr.data), 900)
        self.assertEqual(tr.stats.npts, 900)
        self.assertEqual(tr.stats.sampling_rate, 200.0)
        self.assertEqual(tr.stats.starttime, start)
        self.assertEqual(tr.stats.endtime, end - 0.5)
        # rtrim 202 samples
        tr = deepcopy(trace)
        tr._rtrim(1.010)
        tr.verify()
        np.testing.assert_array_equal(tr.data[-5:],
                                      np.array([793, 794, 795, 796, 797]))
        self.assertEqual(len(tr.data), 798)
        self.assertEqual(tr.stats.npts, 798)
        self.assertEqual(tr.stats.sampling_rate, 200.0)
        self.assertEqual(tr.stats.starttime, start)
        self.assertEqual(tr.stats.endtime, end - 1.010)
        # rtrim 1 minute via UTCDateTime
        tr = deepcopy(trace)
        tr._rtrim(UTCDateTime(2000, 1, 1, 0, 0, 3, 985000))
        tr.verify()
        np.testing.assert_array_equal(tr.data[-5:],
                                      np.array([793, 794, 795, 796, 797]))
        self.assertEqual(len(tr.data), 798)
        self.assertEqual(tr.stats.npts, 798)
        self.assertEqual(tr.stats.sampling_rate, 200.0)
        self.assertEqual(tr.stats.starttime, start)
        self.assertEqual(tr.stats.endtime, end - 1.010)
        # some sanity checks
        # negative end time
        tr = deepcopy(trace)
        t = UTCDateTime(1999, 12, 31)
        tr._rtrim(t)
        tr.verify()
        self.assertEqual(tr.stats.endtime, t)
        np.testing.assert_array_equal(tr.data, np.empty(0))
        # negative end time with given seconds
        tr = deepcopy(trace)
        tr._rtrim(100)
        tr.verify()
        self.assertEqual(tr.stats.endtime, trace.stats.endtime - 100)
        np.testing.assert_array_equal(tr.data, np.empty(0))
        self.assertEqual(tr.stats.endtime, tr.stats.starttime)
        # end time > start time
        tr = deepcopy(trace)
        t = UTCDateTime(2001)
        tr._rtrim(t)
        tr.verify()
        self.assertEqual(tr.stats.endtime, t)
        np.testing.assert_array_equal(tr.data, np.empty(0))
        self.assertEqual(tr.stats.endtime, tr.stats.starttime)
        # end time > start time given seconds
        tr = deepcopy(trace)
        tr._rtrim(5.1)
        tr.verify()
        delta = int(math.floor(round(5.1 * trace.stats.sampling_rate, 7)))
        endtime = trace.stats.starttime + trace.stats.delta * \
            (trace.stats.npts - delta - 1)
        self.assertEqual(tr.stats.endtime, endtime)
        np.testing.assert_array_equal(tr.data, np.empty(0))
        # end time == start time
        # returns one sample!
        tr = deepcopy(trace)
        tr._rtrim(4.995)
        tr.verify()
        np.testing.assert_array_equal(tr.data, np.array([0]))
        self.assertEqual(len(tr.data), 1)
        self.assertEqual(tr.stats.npts, 1)
        self.assertEqual(tr.stats.sampling_rate, 200.0)
        self.assertEqual(tr.stats.starttime, start)
        self.assertEqual(tr.stats.endtime, start)

    def test_rtrim_with_padding(self):
        """
        Tests the _rtrim() method of the Trace class with padding. It has
        already been tested in the two sided trimming tests. This is just to
        have an explicit test. Also tests issue #429.
        """
        # set up
        trace = Trace(data=np.arange(10))
        start = UTCDateTime(2000, 1, 1, 0, 0, 0, 0)
        trace.stats.starttime = start
        trace.stats.sampling_rate = 1.0
        trace.verify()

        # Pad with no fill_value will mask the additional values.
        tr = trace.copy()
        end = tr.stats.endtime
        tr._rtrim(end + 10, pad=True)
        self.assertEqual(tr.stats.endtime, trace.stats.endtime + 10)
        np.testing.assert_array_equal(tr.data[0:10], np.arange(10))
        # Check that the first couple of entries are not masked.
        self.assertFalse(tr.data[0:10].mask.any())
        # All the other entries should be masked.
        self.assertTrue(tr.data[10:].mask.all())

        # Pad with fill_value.
        tr = trace.copy()
        end = tr.stats.endtime
        tr._rtrim(end + 10, pad=True, fill_value=-33)
        self.assertEqual(tr.stats.endtime, trace.stats.endtime + 10)
        # The first ten entries should not have changed.
        np.testing.assert_array_equal(tr.data[0:10], np.arange(10))
        # The rest should be filled with the fill_value.
        np.testing.assert_array_equal(tr.data[10:], np.ones(10) * -33)

    def test_trim(self):
        """
        Tests the trim method of the Trace class.
        """
        # set up
        trace = Trace(data=np.arange(1001))
        start = UTCDateTime(2000, 1, 1, 0, 0, 0, 0)
        trace.stats.starttime = start
        trace.stats.sampling_rate = 200.0
        end = UTCDateTime(2000, 1, 1, 0, 0, 5, 0)
        trace.verify()
        # rtrim 100 samples
        trace.trim(0.5, 0.5)
        trace.verify()
        np.testing.assert_array_equal(trace.data[-5:],
                                      np.array([896, 897, 898, 899, 900]))
        np.testing.assert_array_equal(trace.data[:5],
                                      np.array([100, 101, 102, 103, 104]))
        self.assertEqual(len(trace.data), 801)
        self.assertEqual(trace.stats.npts, 801)
        self.assertEqual(trace.stats.sampling_rate, 200.0)
        self.assertEqual(trace.stats.starttime, start + 0.5)
        self.assertEqual(trace.stats.endtime, end - 0.5)
        # start time should be before end time
        self.assertRaises(ValueError, trace.trim, end, start)

    def test_trim_all_does_not_change_dtype(self):
        """
        If a Trace is completely trimmed, e.g. no data samples are remaining,
        the dtype should remain unchanged.

        A trace with no data samples is not really senseful but the dtype
        should not be changed anyways.
        """
        # Choose non native dtype.
        tr = Trace(np.arange(100, dtype=np.int16))
        tr.trim(UTCDateTime(10000), UTCDateTime(20000))
        # Assert the result.
        self.assertEqual(len(tr.data), 0)
        self.assertEqual(tr.data.dtype, np.int16)

    def test_add_trace_with_gap(self):
        """
        Tests __add__ method of the Trace class.
        """
        # set up
        tr1 = Trace(data=np.arange(1000))
        tr1.stats.sampling_rate = 200
        start = UTCDateTime(2000, 1, 1, 0, 0, 0, 0)
        tr1.stats.starttime = start
        tr2 = Trace(data=np.arange(0, 1000)[::-1])
        tr2.stats.sampling_rate = 200
        tr2.stats.starttime = start + 10
        # verify
        tr1.verify()
        tr2.verify()
        # add
        trace = tr1 + tr2
        # stats
        self.assertEqual(trace.stats.starttime, start)
        self.assertEqual(trace.stats.endtime, start + 14.995)
        self.assertEqual(trace.stats.sampling_rate, 200)
        self.assertEqual(trace.stats.npts, 3000)
        # data
        self.assertEqual(len(trace), 3000)
        self.assertEqual(trace[0], 0)
        self.assertEqual(trace[999], 999)
        self.assertTrue(ma.is_masked(trace[1000]))
        self.assertTrue(ma.is_masked(trace[1999]))
        self.assertEqual(trace[2000], 999)
        self.assertEqual(trace[2999], 0)
        # verify
        trace.verify()

    def test_add_trace_with_overlap(self):
        """
        Tests __add__ method of the Trace class.
        """
        # set up
        tr1 = Trace(data=np.arange(1000))
        tr1.stats.sampling_rate = 200
        start = UTCDateTime(2000, 1, 1, 0, 0, 0, 0)
        tr1.stats.starttime = start
        tr2 = Trace(data=np.arange(0, 1000)[::-1])
        tr2.stats.sampling_rate = 200
        tr2.stats.starttime = start + 4
        # add
        trace = tr1 + tr2
        # stats
        self.assertEqual(trace.stats.starttime, start)
        self.assertEqual(trace.stats.endtime, start + 8.995)
        self.assertEqual(trace.stats.sampling_rate, 200)
        self.assertEqual(trace.stats.npts, 1800)
        # data
        self.assertEqual(len(trace), 1800)
        self.assertEqual(trace[0], 0)
        self.assertEqual(trace[799], 799)
        self.assertTrue(trace[800].mask)
        self.assertTrue(trace[999].mask)
        self.assertEqual(trace[1000], 799)
        self.assertEqual(trace[1799], 0)
        # verify
        trace.verify()

    def test_add_same_trace(self):
        """
        Tests __add__ method of the Trace class.
        """
        # set up
        tr1 = Trace(data=np.arange(1001))
        # add
        trace = tr1 + tr1
        # should return exact the same values
        self.assertEqual(trace.stats, tr1.stats)
        np.testing.assert_array_equal(trace.data, tr1.data)
        # verify
        trace.verify()

    def test_add_trace_within_trace(self):
        """
        Tests __add__ method of the Trace class.
        """
        # set up
        tr1 = Trace(data=np.arange(1001))
        tr1.stats.sampling_rate = 200
        start = UTCDateTime(2000, 1, 1, 0, 0, 0, 0)
        tr1.stats.starttime = start
        tr2 = Trace(data=np.arange(201))
        tr2.stats.sampling_rate = 200
        tr2.stats.starttime = start + 1
        # add
        trace = tr1 + tr2
        # should return exact the same values like trace 1
        self.assertEqual(trace.stats, tr1.stats)
        mask = np.zeros(len(tr1)).astype(np.bool_)
        mask[200:401] = True
        np.testing.assert_array_equal(trace.data.mask, mask)
        np.testing.assert_array_equal(trace.data.data[:200], tr1.data[:200])
        np.testing.assert_array_equal(trace.data.data[401:], tr1.data[401:])
        # add the other way around
        trace = tr2 + tr1
        # should return exact the same values like trace 1
        self.assertEqual(trace.stats, tr1.stats)
        np.testing.assert_array_equal(trace.data.mask, mask)
        np.testing.assert_array_equal(trace.data.data[:200], tr1.data[:200])
        np.testing.assert_array_equal(trace.data.data[401:], tr1.data[401:])
        # verify
        trace.verify()

    def test_add_gap_and_overlap(self):
        """
        Test order of merging traces.
        """
        # set up
        tr1 = Trace(data=np.arange(1000))
        tr1.stats.sampling_rate = 200
        start = UTCDateTime(2000, 1, 1, 0, 0, 0, 0)
        tr1.stats.starttime = start
        tr2 = Trace(data=np.arange(1000)[::-1])
        tr2.stats.sampling_rate = 200
        tr2.stats.starttime = start + 4
        tr3 = Trace(data=np.arange(1000)[::-1])
        tr3.stats.sampling_rate = 200
        tr3.stats.starttime = start + 12
        # overlap
        overlap = tr1 + tr2
        self.assertEqual(len(overlap), 1800)
        mask = np.zeros(1800).astype(np.bool_)
        mask[800:1000] = True
        np.testing.assert_array_equal(overlap.data.mask, mask)
        np.testing.assert_array_equal(overlap.data.data[:800], tr1.data[:800])
        np.testing.assert_array_equal(overlap.data.data[1000:], tr2.data[200:])
        # overlap + gap
        overlap_gap = overlap + tr3
        self.assertEqual(len(overlap_gap), 3400)
        mask = np.zeros(3400).astype(np.bool_)
        mask[800:1000] = True
        mask[1800:2400] = True
        np.testing.assert_array_equal(overlap_gap.data.mask, mask)
        np.testing.assert_array_equal(overlap_gap.data.data[:800],
                                      tr1.data[:800])
        np.testing.assert_array_equal(overlap_gap.data.data[1000:1800],
                                      tr2.data[200:])
        np.testing.assert_array_equal(overlap_gap.data.data[2400:], tr3.data)
        # gap
        gap = tr2 + tr3
        self.assertEqual(len(gap), 2600)
        mask = np.zeros(2600).astype(np.bool_)
        mask[1000:1600] = True
        np.testing.assert_array_equal(gap.data.mask, mask)
        np.testing.assert_array_equal(gap.data.data[:1000], tr2.data)
        np.testing.assert_array_equal(gap.data.data[1600:], tr3.data)

    def test_add_into_gap(self):
        """
        Test __add__ method of the Trace class
        Adding a trace that fits perfectly into gap in a trace
        """
        my_array = np.arange(6, dtype=np.int32)

        stats = Stats()
        stats.network = 'VI'
        stats['starttime'] = UTCDateTime(2009, 8, 5, 0, 0, 0)
        stats['npts'] = 0
        stats['station'] = 'IKJA'
        stats['channel'] = 'EHZ'
        stats['sampling_rate'] = 1

        bigtrace = Trace(data=np.array([], dtype=np.int32), header=stats)
        bigtrace_sort = bigtrace.copy()
        stats['npts'] = len(my_array)
        my_trace = Trace(data=my_array, header=stats)

        stats['npts'] = 2
        trace1 = Trace(data=my_array[0:2].copy(), header=stats)
        stats['starttime'] = UTCDateTime(2009, 8, 5, 0, 0, 2)
        trace2 = Trace(data=my_array[2:4].copy(), header=stats)
        stats['starttime'] = UTCDateTime(2009, 8, 5, 0, 0, 4)
        trace3 = Trace(data=my_array[4:6].copy(), header=stats)

        tr1 = bigtrace
        tr2 = bigtrace_sort
        for method in [0, 1]:
            # Random
            bigtrace = tr1.copy()
            bigtrace = bigtrace.__add__(trace1, method=method)
            bigtrace = bigtrace.__add__(trace3, method=method)
            bigtrace = bigtrace.__add__(trace2, method=method)

            # Sorted
            bigtrace_sort = tr2.copy()
            bigtrace_sort = bigtrace_sort.__add__(trace1, method=method)
            bigtrace_sort = bigtrace_sort.__add__(trace2, method=method)
            bigtrace_sort = bigtrace_sort.__add__(trace3, method=method)

            for tr in (bigtrace, bigtrace_sort):
                self.assertTrue(isinstance(tr, Trace))
                self.assertFalse(isinstance(tr.data, np.ma.masked_array))

            self.assertTrue((bigtrace_sort.data == my_array).all())

            fail_pattern = "\n\tExpected %s\n\tbut got  %s"
            failinfo = fail_pattern % (my_trace, bigtrace_sort)
            failinfo += fail_pattern % (my_trace.data, bigtrace_sort.data)
            self.assertEqual(bigtrace_sort, my_trace, failinfo)

            failinfo = fail_pattern % (my_array, bigtrace.data)
            self.assertTrue((bigtrace.data == my_array).all(), failinfo)

            failinfo = fail_pattern % (my_trace, bigtrace)
            failinfo += fail_pattern % (my_trace.data, bigtrace.data)
            self.assertEqual(bigtrace, my_trace, failinfo)

            for array_ in (bigtrace.data, bigtrace_sort.data):
                failinfo = fail_pattern % (my_array.dtype, array_.dtype)
                self.assertEqual(my_array.dtype, array_.dtype, failinfo)

    def test_slice(self):
        """
        Tests the slicing of trace objects.
        """
        tr = Trace(data=np.arange(10, dtype=np.int32))
        mempos = tr.data.ctypes.data
        t = tr.stats.starttime
        tr1 = tr.slice(t + 2, t + 8)
        tr1.data[0] = 10
        self.assertEqual(tr.data[2], 10)
        self.assertEqual(tr.data.ctypes.data, mempos)
        self.assertEqual(tr.data[2:9].ctypes.data, tr1.data.ctypes.data)
        self.assertEqual(tr1.data.ctypes.data - 8, mempos)

        # Test the processing information for the slicing. The sliced trace
        # should have a processing information showing that it has been
        # trimmed. The original trace should have nothing.
        tr = Trace(data=np.arange(10, dtype=np.int32))
        tr2 = tr.slice(tr.stats.starttime)
        self.assertNotIn("processing", tr.stats)
        self.assertIn("processing", tr2.stats)
        self.assertIn("trim", tr2.stats.processing[0])

    def test_slice_no_starttime_or_endtime(self):
        """
        Tests the slicing of trace objects with no start time or end time
        provided. Compares results against the equivalent trim() operation
        """
        tr_orig = Trace(data=np.arange(10, dtype=np.int32))
        tr = tr_orig.copy()
        # two time points outside the trace and two inside
        t1 = tr.stats.starttime - 2
        t2 = tr.stats.starttime + 2
        t3 = tr.stats.endtime - 3
        t4 = tr.stats.endtime + 2

        # test 1: only removing data at left side
        tr_trim = tr_orig.copy()
        tr_trim.trim(starttime=t2)
        self.assertEqual(tr_trim, tr.slice(starttime=t2))
        tr2 = tr.slice(starttime=t2, endtime=t4)
        self.__remove_processing(tr_trim)
        self.__remove_processing(tr2)
        self.assertEqual(tr_trim, tr2)

        # test 2: only removing data at right side
        tr_trim = tr_orig.copy()
        tr_trim.trim(endtime=t3)
        self.assertEqual(tr_trim, tr.slice(endtime=t3))
        tr2 = tr.slice(starttime=t1, endtime=t3)
        self.__remove_processing(tr_trim)
        self.__remove_processing(tr2)
        self.assertEqual(tr_trim, tr2)

        # test 3: not removing data at all
        tr_trim = tr_orig.copy()
        tr_trim.trim(starttime=t1, endtime=t4)
        tr2 = tr.slice()
        self.__remove_processing(tr_trim)
        self.__remove_processing(tr2)
        self.assertEqual(tr_trim, tr2)

        tr2 = tr.slice(starttime=t1)
        self.__remove_processing(tr_trim)
        self.__remove_processing(tr2)
        self.assertEqual(tr_trim, tr2)

        tr2 = tr.slice(endtime=t4)
        self.__remove_processing(tr2)
        self.assertEqual(tr_trim, tr2)

        tr2 = tr.slice(starttime=t1, endtime=t4)
        self.__remove_processing(tr2)
        self.assertEqual(tr_trim, tr2)

        tr_trim.trim()
        tr2 = tr.slice()
        self.__remove_processing(tr_trim)
        self.__remove_processing(tr2)
        self.assertEqual(tr_trim, tr2)

        tr2 = tr.slice(starttime=t1)
        self.__remove_processing(tr_trim)
        self.__remove_processing(tr2)
        self.assertEqual(tr_trim, tr2)

        tr2 = tr.slice(endtime=t4)
        self.__remove_processing(tr_trim)
        self.__remove_processing(tr2)
        self.assertEqual(tr_trim, tr2)

        tr2 = tr.slice(starttime=t1, endtime=t4)
        self.__remove_processing(tr_trim)
        self.__remove_processing(tr2)
        self.assertEqual(tr_trim, tr2)

        # test 4: removing data at left and right side
        tr_trim = tr_orig.copy()
        tr_trim.trim(starttime=t2, endtime=t3)
        self.assertEqual(tr_trim, tr.slice(t2, t3))
        self.assertEqual(tr_trim, tr.slice(starttime=t2, endtime=t3))

        # test 5: no data left after operation
        tr_trim = tr_orig.copy()
        tr_trim.trim(starttime=t4)

        tr2 = tr.slice(starttime=t4)
        self.__remove_processing(tr_trim)
        self.__remove_processing(tr2)
        self.assertEqual(tr_trim, tr2)

        tr2 = tr.slice(starttime=t4, endtime=t4 + 1)
        self.__remove_processing(tr_trim)
        self.__remove_processing(tr2)
        self.assertEqual(tr_trim, tr2)

    def test_slice_nearest_sample(self):
        """
        Tests slicing with the nearest sample flag set to on or off.
        """
        tr = Trace(data=np.arange(6))
        # Samples at:
        # 0       10       20       30       40       50
        tr.stats.sampling_rate = 0.1

        # Nearest sample flag defaults to true.
        tr2 = tr.slice(UTCDateTime(4), UTCDateTime(44))
        self.assertEqual(tr2.stats.starttime, UTCDateTime(0))
        self.assertEqual(tr2.stats.endtime, UTCDateTime(40))

        tr2 = tr.slice(UTCDateTime(8), UTCDateTime(48))
        self.assertEqual(tr2.stats.starttime, UTCDateTime(10))
        self.assertEqual(tr2.stats.endtime, UTCDateTime(50))

        # Setting it to False changes the returned values.
        tr2 = tr.slice(UTCDateTime(4), UTCDateTime(44), nearest_sample=False)
        self.assertEqual(tr2.stats.starttime, UTCDateTime(10))
        self.assertEqual(tr2.stats.endtime, UTCDateTime(40))

        tr2 = tr.slice(UTCDateTime(8), UTCDateTime(48), nearest_sample=False)
        self.assertEqual(tr2.stats.starttime, UTCDateTime(10))
        self.assertEqual(tr2.stats.endtime, UTCDateTime(40))

    def test_trim_floating_point(self):
        """
        Tests the slicing of trace objects.
        """
        # Create test array that allows for easy testing.
        tr = Trace(data=np.arange(11))
        org_stats = deepcopy(tr.stats)
        org_data = deepcopy(tr.data)
        # Save memory position of array.
        mem_pos = tr.data.ctypes.data
        # Just some sanity tests.
        self.assertEqual(tr.stats.starttime, UTCDateTime(0))
        self.assertEqual(tr.stats.endtime, UTCDateTime(10))
        # Create temp trace object used for testing.
        st = tr.stats.starttime
        # This is supposed to include the start and end times and should
        # therefore cut right at 2 and 8.
        temp = deepcopy(tr)
        temp.trim(st + 2.1, st + 7.1)
        # Should be identical.
        temp2 = deepcopy(tr)
        temp2.trim(st + 2.0, st + 8.0)
        self.assertEqual(temp.stats.starttime, UTCDateTime(2))
        self.assertEqual(temp.stats.endtime, UTCDateTime(7))
        self.assertEqual(temp.stats.npts, 6)
        self.assertEqual(temp2.stats.npts, 7)
        # self.assertEqual(temp.stats, temp2.stats)
        np.testing.assert_array_equal(temp.data, temp2.data[:-1])
        # Create test array that allows for easy testing.
        # Check if the data is the same.
        self.assertNotEqual(temp.data.ctypes.data, tr.data[2:9].ctypes.data)
        np.testing.assert_array_equal(tr.data[2:8], temp.data)
        # Using out of bounds times should not do anything but create
        # a copy of the stats.
        temp = deepcopy(tr)
        temp.trim(st - 2.5, st + 200)
        # The start and end times should not change.
        self.assertEqual(temp.stats.starttime, UTCDateTime(0))
        self.assertEqual(temp.stats.endtime, UTCDateTime(10))
        self.assertEqual(temp.stats.npts, 11)
        # Alter the new stats to make sure the old one stays intact.
        temp.stats.starttime = UTCDateTime(1000)
        self.assertEqual(org_stats, tr.stats)
        # Check if the data address is not the same, that is it is a copy
        self.assertNotEqual(temp.data.ctypes.data, tr.data.ctypes.data)
        np.testing.assert_array_equal(tr.data, temp.data)
        # Make sure the original Trace object did not change.
        np.testing.assert_array_equal(tr.data, org_data)
        self.assertEqual(tr.data.ctypes.data, mem_pos)
        self.assertEqual(tr.stats, org_stats)
        # Use more complicated times and sampling rate.
        tr = Trace(data=np.arange(111))
        tr.stats.starttime = UTCDateTime(111.11111)
        tr.stats.sampling_rate = 50.0
        org_stats = deepcopy(tr.stats)
        org_data = deepcopy(tr.data)
        # Save memory position of array.
        mem_pos = tr.data.ctypes.data
        # Create temp trace object used for testing.
        temp = deepcopy(tr)
        temp.trim(UTCDateTime(111.22222), UTCDateTime(112.99999),
                  nearest_sample=False)
        # Should again be identical. XXX NOT!
        temp2 = deepcopy(tr)
        temp2.trim(UTCDateTime(111.21111), UTCDateTime(113.01111),
                   nearest_sample=False)
        np.testing.assert_array_equal(temp.data, temp2.data[1:-1])
        # Check stuff.
        self.assertEqual(temp.stats.starttime, UTCDateTime(111.23111))
        self.assertEqual(temp.stats.endtime, UTCDateTime(112.991110))
        # Check if the data is the same.
        temp = deepcopy(tr)
        temp.trim(UTCDateTime(0), UTCDateTime(1000 * 1000))
        self.assertNotEqual(temp.data.ctypes.data, tr.data.ctypes.data)
        # starttime must be in conformance with sampling rate
        t = UTCDateTime(111.11111)
        self.assertEqual(temp.stats.starttime, t)
        delta = int((tr.stats.starttime - t) * tr.stats.sampling_rate + .5)
        np.testing.assert_array_equal(tr.data, temp.data[delta:delta + 111])
        # Make sure the original Trace object did not change.
        np.testing.assert_array_equal(tr.data, org_data)
        self.assertEqual(tr.data.ctypes.data, mem_pos)
        self.assertEqual(tr.stats, org_stats)

    def test_trim_floating_point_with_padding_1(self):
        """
        Tests the slicing of trace objects with the use of the padding option.
        """
        # Create test array that allows for easy testing.
        tr = Trace(data=np.arange(11))
        org_stats = deepcopy(tr.stats)
        org_data = deepcopy(tr.data)
        # Save memory position of array.
        mem_pos = tr.data.ctypes.data
        # Just some sanity tests.
        self.assertEqual(tr.stats.starttime, UTCDateTime(0))
        self.assertEqual(tr.stats.endtime, UTCDateTime(10))
        # Create temp trace object used for testing.
        st = tr.stats.starttime
        # Using out of bounds times should not do anything but create
        # a copy of the stats.
        temp = deepcopy(tr)
        temp.trim(st - 2.5, st + 200, pad=True)
        self.assertEqual(temp.stats.starttime.timestamp, -2.0)
        self.assertEqual(temp.stats.endtime.timestamp, 200)
        self.assertEqual(temp.stats.npts, 203)
        mask = np.zeros(203).astype(np.bool_)
        mask[:2] = True
        mask[13:] = True
        np.testing.assert_array_equal(temp.data.mask, mask)
        # Alter the new stats to make sure the old one stays intact.
        temp.stats.starttime = UTCDateTime(1000)
        self.assertEqual(org_stats, tr.stats)
        # Check if the data address is not the same, that is it is a copy
        self.assertNotEqual(temp.data.ctypes.data, tr.data.ctypes.data)
        np.testing.assert_array_equal(tr.data, temp.data[2:13])
        # Make sure the original Trace object did not change.
        np.testing.assert_array_equal(tr.data, org_data)
        self.assertEqual(tr.data.ctypes.data, mem_pos)
        self.assertEqual(tr.stats, org_stats)

    def test_trim_floating_point_with_padding_2(self):
        """
        Use more complicated times and sampling rate.
        """
        tr = Trace(data=np.arange(111))
        tr.stats.starttime = UTCDateTime(111.11111)
        tr.stats.sampling_rate = 50.0
        org_stats = deepcopy(tr.stats)
        org_data = deepcopy(tr.data)
        # Save memory position of array.
        mem_pos = tr.data.ctypes.data
        # Create temp trace object used for testing.
        temp = deepcopy(tr)
        temp.trim(UTCDateTime(111.22222), UTCDateTime(112.99999),
                  nearest_sample=False)
        # Should again be identical.#XXX not
        temp2 = deepcopy(tr)
        temp2.trim(UTCDateTime(111.21111), UTCDateTime(113.01111),
                   nearest_sample=False)
        np.testing.assert_array_equal(temp.data, temp2.data[1:-1])
        # Check stuff.
        self.assertEqual(temp.stats.starttime, UTCDateTime(111.23111))
        self.assertEqual(temp.stats.endtime, UTCDateTime(112.991110))
        # Check if the data is the same.
        temp = deepcopy(tr)
        temp.trim(UTCDateTime(0), UTCDateTime(1000 * 1000), pad=True)
        self.assertNotEqual(temp.data.ctypes.data, tr.data.ctypes.data)
        # starttime must be in conformance with sampling rate
        t = UTCDateTime(1969, 12, 31, 23, 59, 59, 991110)
        self.assertEqual(temp.stats.starttime, t)
        delta = int((tr.stats.starttime - t) * tr.stats.sampling_rate + .5)
        np.testing.assert_array_equal(tr.data, temp.data[delta:delta + 111])
        # Make sure the original Trace object did not change.
        np.testing.assert_array_equal(tr.data, org_data)
        self.assertEqual(tr.data.ctypes.data, mem_pos)
        self.assertEqual(tr.stats, org_stats)

    def test_add_sanity(self):
        """
        Test sanity checks in __add__ method of the Trace object.
        """
        tr = Trace(data=np.arange(10))
        # you may only add a Trace object
        self.assertRaises(TypeError, tr.__add__, 1234)
        self.assertRaises(TypeError, tr.__add__, '1234')
        self.assertRaises(TypeError, tr.__add__, [1, 2, 3, 4])
        # trace id
        tr2 = Trace()
        tr2.stats.station = 'TEST'
        self.assertRaises(TypeError, tr.__add__, tr2)
        # sample rate
        tr2 = Trace()
        tr2.stats.sampling_rate = 20
        self.assertRaises(TypeError, tr.__add__, tr2)
        # calibration factor
        tr2 = Trace()
        tr2.stats.calib = 20
        self.assertRaises(TypeError, tr.__add__, tr2)
        # data type
        tr2 = Trace()
        tr2.data = np.arange(10, dtype=np.float32)
        self.assertRaises(TypeError, tr.__add__, tr2)

    def test_add_overlaps_default_method(self):
        """
        Test __add__ method of the Trace object.
        """
        # 1
        # overlapping trace with differing data
        # Trace 1: 0000000
        # Trace 2:      1111111
        tr1 = Trace(data=np.zeros(7))
        tr2 = Trace(data=np.ones(7))
        tr2.stats.starttime = tr1.stats.starttime + 5
        # 1 + 2  : 00000--11111
        tr = tr1 + tr2
        self.assertTrue(isinstance(tr.data, np.ma.masked_array))
        self.assertEqual(tr.data.tolist(),
                         [0, 0, 0, 0, 0, None, None, 1, 1, 1, 1, 1])
        # 2 + 1  : 00000--11111
        tr = tr2 + tr1
        self.assertTrue(isinstance(tr.data, np.ma.masked_array))
        self.assertEqual(tr.data.tolist(),
                         [0, 0, 0, 0, 0, None, None, 1, 1, 1, 1, 1])
        # 2
        # overlapping trace with same data
        # Trace 1: 0000000
        # Trace 2:      0000000
        tr1 = Trace(data=np.zeros(7))
        tr2 = Trace(data=np.zeros(7))
        tr2.stats.starttime = tr1.stats.starttime + 5
        # 1 + 2  : 000000000000
        tr = tr1 + tr2
        self.assertTrue(isinstance(tr.data, np.ndarray))
        np.testing.assert_array_equal(tr.data, np.zeros(12))
        # 2 + 1  : 000000000000
        tr = tr2 + tr1
        self.assertTrue(isinstance(tr.data, np.ndarray))
        np.testing.assert_array_equal(tr.data, np.zeros(12))
        # 3
        # contained trace with same data
        # Trace 1: 1111111111
        # Trace 2:      11
        tr1 = Trace(data=np.ones(10))
        tr2 = Trace(data=np.ones(2))
        tr2.stats.starttime = tr1.stats.starttime + 5
        # 1 + 2  : 1111111111
        tr = tr1 + tr2
        self.assertTrue(isinstance(tr.data, np.ndarray))
        np.testing.assert_array_equal(tr.data, np.ones(10))
        # 2 + 1  : 1111111111
        tr = tr2 + tr1
        self.assertTrue(isinstance(tr.data, np.ndarray))
        np.testing.assert_array_equal(tr.data, np.ones(10))
        # 4
        # contained trace with differing data
        # Trace 1: 0000000000
        # Trace 2:      11
        tr1 = Trace(data=np.zeros(10))
        tr2 = Trace(data=np.ones(2))
        tr2.stats.starttime = tr1.stats.starttime + 5
        # 1 + 2  : 00000--000
        tr = tr1 + tr2
        self.assertTrue(isinstance(tr.data, np.ma.masked_array))
        self.assertEqual(tr.data.tolist(),
                         [0, 0, 0, 0, 0, None, None, 0, 0, 0])
        # 2 + 1  : 00000--000
        tr = tr2 + tr1
        self.assertTrue(isinstance(tr.data, np.ma.masked_array))
        self.assertEqual(tr.data.tolist(),
                         [0, 0, 0, 0, 0, None, None, 0, 0, 0])
        # 5
        # completely contained trace with same data until end
        # Trace 1: 1111111111
        # Trace 2: 1111111111
        tr1 = Trace(data=np.ones(10))
        tr2 = Trace(data=np.ones(10))
        # 1 + 2  : 1111111111
        tr = tr1 + tr2
        self.assertTrue(isinstance(tr.data, np.ndarray))
        np.testing.assert_array_equal(tr.data, np.ones(10))
        # 6
        # completely contained trace with differing data
        # Trace 1: 0000000000
        # Trace 2: 1111111111
        tr1 = Trace(data=np.zeros(10))
        tr2 = Trace(data=np.ones(10))
        # 1 + 2  : ----------
        tr = tr1 + tr2
        self.assertTrue(isinstance(tr.data, np.ma.masked_array))
        self.assertEqual(tr.data.tolist(), [None] * 10)

    def test_add_with_different_sampling_rates(self):
        """
        Test __add__ method of the Trace object.
        """
        # 1 - different sampling rates for the same channel should fail
        tr1 = Trace(data=np.zeros(5))
        tr1.stats.sampling_rate = 200
        tr2 = Trace(data=np.zeros(5))
        tr2.stats.sampling_rate = 50
        self.assertRaises(TypeError, tr1.__add__, tr2)
        self.assertRaises(TypeError, tr2.__add__, tr1)
        # 2 - different sampling rates for the different channels works
        tr1 = Trace(data=np.zeros(5))
        tr1.stats.sampling_rate = 200
        tr1.stats.channel = 'EHE'
        tr2 = Trace(data=np.zeros(5))
        tr2.stats.sampling_rate = 50
        tr2.stats.channel = 'EHZ'
        tr3 = Trace(data=np.zeros(5))
        tr3.stats.sampling_rate = 200
        tr3.stats.channel = 'EHE'
        tr4 = Trace(data=np.zeros(5))
        tr4.stats.sampling_rate = 50
        tr4.stats.channel = 'EHZ'
        # same sampling rate and ids should not fail
        tr1 + tr3
        tr3 + tr1
        tr2 + tr4
        tr4 + tr2

    def test_add_with_different_datatypes_or_id(self):
        """
        Test __add__ method of the Trace object.
        """
        # 1 - different data types for the same channel should fail
        tr1 = Trace(data=np.zeros(5, dtype=np.int32))
        tr2 = Trace(data=np.zeros(5, dtype=np.float32))
        self.assertRaises(TypeError, tr1.__add__, tr2)
        self.assertRaises(TypeError, tr2.__add__, tr1)
        # 2 - different sampling rates for the different channels works
        tr1 = Trace(data=np.zeros(5, dtype=np.int32))
        tr1.stats.channel = 'EHE'
        tr2 = Trace(data=np.zeros(5, dtype=np.float32))
        tr2.stats.channel = 'EHZ'
        tr3 = Trace(data=np.zeros(5, dtype=np.int32))
        tr3.stats.channel = 'EHE'
        tr4 = Trace(data=np.zeros(5, dtype=np.float32))
        tr4.stats.channel = 'EHZ'
        # same data types and ids should not fail
        tr1 + tr3
        tr3 + tr1
        tr2 + tr4
        tr4 + tr2
        # adding traces with different ids should raise
        self.assertRaises(TypeError, tr1.__add__, tr2)
        self.assertRaises(TypeError, tr3.__add__, tr4)
        self.assertRaises(TypeError, tr2.__add__, tr1)
        self.assertRaises(TypeError, tr4.__add__, tr3)

    def test_comparisons(self):
        """
        Tests all rich comparison operators (==, !=, <, <=, >, >=)
        The latter four are not implemented due to ambiguous meaning and bounce
        an error.
        """
        # create test traces
        tr0 = Trace(np.arange(3))
        tr1 = Trace(np.arange(3))
        tr2 = Trace(np.arange(3), {'station': 'X'})
        tr3 = Trace(np.arange(3), {'processing':
                                   ["filter:lowpass:{'freq': 10}"]})
        tr4 = Trace(np.arange(5))
        tr5 = Trace(np.arange(5), {'station': 'X'})
        tr6 = Trace(np.arange(5), {'processing':
                                   ["filter:lowpass:{'freq': 10}"]})
        tr7 = Trace(np.array([1, 1, 1]))
        # tests that should raise a NotImplementedError (i.e. <=, <, >=, >)
        self.assertRaises(NotImplementedError, tr1.__lt__, tr1)
        self.assertRaises(NotImplementedError, tr1.__le__, tr1)
        self.assertRaises(NotImplementedError, tr1.__gt__, tr1)
        self.assertRaises(NotImplementedError, tr1.__ge__, tr1)
        self.assertRaises(NotImplementedError, tr1.__lt__, tr2)
        self.assertRaises(NotImplementedError, tr1.__le__, tr2)
        self.assertRaises(NotImplementedError, tr1.__gt__, tr2)
        self.assertRaises(NotImplementedError, tr1.__ge__, tr2)
        # normal tests
        self.assertEqual(tr0 == tr0, True)
        self.assertEqual(tr0 == tr1, True)
        self.assertEqual(tr0 == tr2, False)
        self.assertEqual(tr0 == tr3, False)
        self.assertEqual(tr0 == tr4, False)
        self.assertEqual(tr0 == tr5, False)
        self.assertEqual(tr0 == tr6, False)
        self.assertEqual(tr0 == tr7, False)
        self.assertEqual(tr5 == tr0, False)
        self.assertEqual(tr5 == tr1, False)
        self.assertEqual(tr5 == tr2, False)
        self.assertEqual(tr5 == tr3, False)
        self.assertEqual(tr5 == tr4, False)
        self.assertEqual(tr5 == tr5, True)
        self.assertEqual(tr5 == tr6, False)
        self.assertEqual(tr3 == tr6, False)
        self.assertEqual(tr0 != tr0, False)
        self.assertEqual(tr0 != tr1, False)
        self.assertEqual(tr0 != tr2, True)
        self.assertEqual(tr0 != tr3, True)
        self.assertEqual(tr0 != tr4, True)
        self.assertEqual(tr0 != tr5, True)
        self.assertEqual(tr0 != tr6, True)
        self.assertEqual(tr0 != tr7, True)
        self.assertEqual(tr5 != tr0, True)
        self.assertEqual(tr5 != tr1, True)
        self.assertEqual(tr5 != tr2, True)
        self.assertEqual(tr5 != tr3, True)
        self.assertEqual(tr5 != tr4, True)
        self.assertEqual(tr5 != tr5, False)
        self.assertEqual(tr5 != tr6, True)
        self.assertEqual(tr3 != tr6, True)
        # some weirder tests against non-Trace objects
        for object in [0, 1, 0.0, 1.0, "", "test", True, False, [], [tr0],
                       set(), set(tr0), {}, {"test": "test"}, [], None, ]:
            self.assertEqual(tr0 == object, False)
            self.assertEqual(tr0 != object, True)

    def test_nearest_sample(self):
        """
        This test case shows that the libmseed is actually flooring the
        starttime to the next sample value, regardless if it is the nearest
        sample. The flag nearest_sample=True tries to avoids this and
        rounds it to the next actual possible sample point.
        """
        # set up
        trace = Trace(data=np.empty(10000))
        trace.stats.starttime = UTCDateTime("2010-06-20T20:19:40.000000Z")
        trace.stats.sampling_rate = 200.0
        # ltrim
        tr = deepcopy(trace)
        t = UTCDateTime("2010-06-20T20:19:51.494999Z")
        tr._ltrim(t - 3, nearest_sample=True)
        # see that it is actually rounded to the next sample point
        self.assertEqual(tr.stats.starttime,
                         UTCDateTime("2010-06-20T20:19:48.495000Z"))
        # Lots of tests follow that thoroughly check the cutting behavior
        # using nearest_sample=True/False
        # rtrim
        tr = deepcopy(trace)
        t = UTCDateTime("2010-06-20T20:19:51.494999Z")
        tr._rtrim(t + 7, nearest_sample=True)
        # see that it is actually rounded to the next sample point
        self.assertEqual(tr.stats.endtime,
                         UTCDateTime("2010-06-20T20:19:58.495000Z"))
        tr = deepcopy(trace)
        t = UTCDateTime("2010-06-20T20:19:51.495000Z")
        tr._rtrim(t + 7, nearest_sample=True)
        # see that it is actually rounded to the next sample point
        self.assertEqual(tr.stats.endtime,
                         UTCDateTime("2010-06-20T20:19:58.495000Z"))
        tr = deepcopy(trace)
        t = UTCDateTime("2010-06-20T20:19:51.495111Z")
        tr._rtrim(t + 7, nearest_sample=True)
        # see that it is actually rounded to the next sample point
        self.assertEqual(tr.stats.endtime,
                         UTCDateTime("2010-06-20T20:19:58.495000Z"))
        tr = deepcopy(trace)
        t = UTCDateTime("2010-06-20T20:19:51.497501Z")
        tr._rtrim(t + 7, nearest_sample=True)
        # see that it is actually rounded to the next sample point
        self.assertEqual(tr.stats.endtime,
                         UTCDateTime("2010-06-20T20:19:58.500000Z"))
        # rtrim
        tr = deepcopy(trace)
        t = UTCDateTime("2010-06-20T20:19:51.494999Z")
        tr._rtrim(t + 7, nearest_sample=False)
        # see that it is actually rounded to the next sample point
        self.assertEqual(tr.stats.endtime,
                         UTCDateTime("2010-06-20T20:19:58.490000Z"))
        tr = deepcopy(trace)
        t = UTCDateTime("2010-06-20T20:19:51.495000Z")
        tr._rtrim(t + 7, nearest_sample=False)
        # see that it is actually rounded to the next sample point
        self.assertEqual(tr.stats.endtime,
                         UTCDateTime("2010-06-20T20:19:58.495000Z"))
        tr = deepcopy(trace)
        t = UTCDateTime("2010-06-20T20:19:51.495111Z")
        tr._rtrim(t + 7, nearest_sample=False)
        # see that it is actually rounded to the next sample point
        self.assertEqual(tr.stats.endtime,
                         UTCDateTime("2010-06-20T20:19:58.495000Z"))
        tr = deepcopy(trace)
        t = UTCDateTime("2010-06-20T20:19:51.497500Z")
        tr._rtrim(t + 7, nearest_sample=False)
        # see that it is actually rounded to the next sample point
        self.assertEqual(tr.stats.endtime,
                         UTCDateTime("2010-06-20T20:19:58.495000Z"))

    def test_masked_array_to_string(self):
        """
        Masked arrays should be marked using __str__.
        """
        st = read()
        overlaptrace = st[0].copy()
        overlaptrace.stats.starttime += 1
        st.append(overlaptrace)
        st.merge()
        out = st[0].__str__()
        self.assertTrue(out.endswith('(masked)'))

    def test_detrend(self):
        """
        Test detrend method of trace
        """
        t = np.arange(10)
        data = 0.1 * t + 1.
        tr = Trace(data=data.copy())

        tr.detrend(type='simple')
        np.testing.assert_array_almost_equal(tr.data, np.zeros(10))

        tr.data = data.copy()
        tr.detrend(type='linear')
        np.testing.assert_array_almost_equal(tr.data, np.zeros(10))

        data = np.zeros(10)
        data[3:7] = 1.

        tr.data = data.copy()
        tr.detrend(type='simple')
        np.testing.assert_almost_equal(tr.data[0], 0.)
        np.testing.assert_almost_equal(tr.data[-1], 0.)

        tr.data = data.copy()
        tr.detrend(type='linear')
        np.testing.assert_almost_equal(tr.data[0], -0.4)
        np.testing.assert_almost_equal(tr.data[-1], -0.4)

    def test_differentiate(self):
        """
        Test differentiation method of trace
        """
        t = np.linspace(0., 1., 11)
        data = 0.1 * t + 1.
        tr = Trace(data=data)
        tr.stats.delta = 0.1
        tr.differentiate(method='gradient')
        np.testing.assert_array_almost_equal(tr.data, np.ones(11) * 0.1)

    def test_integrate(self):
        """
        Test integration method of trace
        """
        data = np.ones(101) * 0.01
        tr = Trace(data=data)
        tr.stats.delta = 0.1
        tr.integrate()
        # Assert time and length of resulting array.
        self.assertEqual(tr.stats.starttime, UTCDateTime(0))
        self.assertEqual(tr.stats.npts, 101)
        np.testing.assert_array_almost_equal(
            tr.data, np.concatenate([[0.0], np.cumsum(data)[:-1] * 0.1]))

    def test_issue_317(self):
        """
        Tests times after breaking a stream into parts and merging it again.
        """
        # create a sample trace
        org_trace = Trace(data=np.arange(22487))
        org_trace.stats.starttime = UTCDateTime()
        org_trace.stats.sampling_rate = 0.999998927116
        num_pakets = 10
        # break org_trace into set of contiguous packet data
        traces = []
        packet_length = int(np.size(org_trace.data) / num_pakets)
        delta_time = org_trace.stats.delta
        tstart = org_trace.stats.starttime
        tend = tstart + delta_time * float(packet_length - 1)
        for i in range(num_pakets):
            tr = Trace(org_trace.data, org_trace.stats)
            tr = tr.slice(tstart, tend)
            traces.append(tr)
            tstart = tr.stats.endtime + delta_time
            tend = tstart + delta_time * float(packet_length - 1)
        # reconstruct original trace by adding together packet traces
        sum_trace = traces[0].copy()
        npts = traces[0].stats.npts
        for i in range(1, len(traces)):
            sum_trace = sum_trace.__add__(traces[i].copy(), method=0,
                                          interpolation_samples=0,
                                          fill_value='latest',
                                          sanity_checks=True)
            # check npts
            self.assertEqual(traces[i].stats.npts, npts)
            self.assertEqual(sum_trace.stats.npts, (i + 1) * npts)
            # check data
            np.testing.assert_array_equal(traces[i].data,
                                          np.arange(i * npts, (i + 1) * npts))
            np.testing.assert_array_equal(sum_trace.data,
                                          np.arange(0, (i + 1) * npts))
            # check delta
            self.assertEqual(traces[i].stats.delta, org_trace.stats.delta)
            self.assertEqual(sum_trace.stats.delta, org_trace.stats.delta)
            # check sampling rates
            self.assertAlmostEqual(traces[i].stats.sampling_rate,
                                   org_trace.stats.sampling_rate)
            self.assertAlmostEqual(sum_trace.stats.sampling_rate,
                                   org_trace.stats.sampling_rate)
            # check end times
            self.assertEqual(traces[i].stats.endtime, sum_trace.stats.endtime)

    def test_verify(self):
        """
        Tests verify method.
        """
        # empty Trace
        tr = Trace()
        tr.verify()
        # Trace with a single sample (issue #357)
        tr = Trace(data=np.array([1]))
        tr.verify()
        # example Trace
        tr = read()[0]
        tr.verify()

    def test_percent_in_str(self):
        """
        Tests if __str__ method is working with percent sign (%).
        """
        tr = Trace()
        tr.stats.station = '%t3u'
        self.assertTrue(tr.__str__().startswith(".%t3u.. | 1970"))

    def test_taper(self):
        """
        Test taper method of trace
        """
        data = np.ones(10)
        tr = Trace(data=data)
        tr.taper(max_percentage=0.05, type='cosine')
        for i in range(len(data)):
            self.assertLessEqual(tr.data[i], 1.)
            self.assertGreaterEqual(tr.data[i], 0.)

    def test_taper_onesided(self):
        """
        Test onesided taper method of trace
        """
        data = np.ones(11)
        tr = Trace(data=data)
        # overlong taper - raises UserWarning - ignoring
        with warnings.catch_warnings(record=True):
            warnings.simplefilter("ignore", UserWarning)
            tr.taper(max_percentage=None, side="left")
        self.assertTrue(tr.data[:5].sum() < 5.)
        self.assertEqual(tr.data[6:].sum(), 5.)

        data = np.ones(11)
        tr = Trace(data=data)
        # overlong taper - raises UserWarning - ignoring
        with warnings.catch_warnings(record=True):
            warnings.simplefilter("ignore", UserWarning)
            tr.taper(max_percentage=None, side="right")
        self.assertEqual(tr.data[:5].sum(), 5.)
        self.assertTrue(tr.data[6:].sum() < 5.)

    def test_taper_length(self):
        npts = 11
        type_ = "hann"

        data = np.ones(npts)
        tr = Trace(data=data, header={'sampling': 1.})
        # test an overlong taper request, still works but raises UserWarning
        with warnings.catch_warnings(record=True) as w:
            warnings.simplefilter("always", UserWarning)
            tr.taper(max_percentage=0.7, max_length=int(npts / 2) + 1)
        self.assertEqual(w[0].category, UserWarning)

        data = np.ones(npts)
        tr = Trace(data=data, header={'sampling': 1.})
        # first 3 samples get tapered
        tr.taper(max_percentage=None, type=type_, side="left", max_length=3)
        # last 5 samples get tapered
        tr.taper(max_percentage=0.5, type=type_, side="right", max_length=None)
        self.assertTrue(np.all(tr.data[:3] < 1.))
        self.assertTrue(np.all(tr.data[3:6] == 1.))
        self.assertTrue(np.all(tr.data[6:] < 1.))

        data = np.ones(npts)
        tr = Trace(data=data, header={'sampling': 1.})
        # first 3 samples get tapered
        tr.taper(max_percentage=0.5, type=type_, side="left", max_length=3)
        # last 3 samples get tapered
        tr.taper(max_percentage=0.3, type=type_, side="right", max_length=5)
        self.assertTrue(np.all(tr.data[:3] < 1.))
        self.assertTrue(np.all(tr.data[3:8] == 1.))
        self.assertTrue(np.all(tr.data[8:] < 1.))

    def test_times(self):
        """
        Test if the correct times array is returned for normal traces and
        traces with gaps.
        """
        tr = Trace(data=np.ones(100))
        tr.stats.sampling_rate = 20
        delta = tr.stats.delta
        start = UTCDateTime(2000, 1, 1, 0, 0, 0, 0)
        tr.stats.starttime = start
        tm = tr.times()
        self.assertAlmostEqual(tm[-1], tr.stats.endtime - tr.stats.starttime)
        tr.data = np.ma.ones(100)
        tr.data[30:40] = np.ma.masked
        tm = tr.times()
        self.assertTrue(np.alltrue(tr.data.mask == tm.mask))
        # test relative with reftime
        tr.data = np.ones(100)
        shift = 9.5
        reftime = start - shift
        got = tr.times(reftime=reftime)
        self.assertEqual(len(got), tr.stats.npts)
        expected = np.arange(shift, shift + 4.5 * delta, delta)
        np.testing.assert_allclose(got[:5], expected, rtol=1e-8)
        # test other options
        got = tr.times("utcdatetime")
        expected = np.array([
            UTCDateTime(2000, 1, 1, 0, 0),
            UTCDateTime(2000, 1, 1, 0, 0, 0, 50000),
            UTCDateTime(2000, 1, 1, 0, 0, 0, 100000),
            UTCDateTime(2000, 1, 1, 0, 0, 0, 150000),
            UTCDateTime(2000, 1, 1, 0, 0, 0, 200000)], dtype=UTCDateTime)
        self.assertTrue(isinstance(got[0], UTCDateTime))
        np.testing.assert_allclose(
            [t_.timestamp for t_ in got[:5]],
            [t_.timestamp for t_ in expected], rtol=1e-17)
        got = tr.times("timestamp")
        expected = np.arange(0, 4.5 * delta, delta) + 946684800.0
        np.testing.assert_allclose(got[:5], expected, rtol=1e-17)
        got = tr.times("matplotlib")
        expected = np.array([
            730120.00000000000000000000, 730120.00000057870056480169,
            730120.00000115740112960339, 730120.00000173610169440508,
            730120.00000231480225920677])
        np.testing.assert_allclose(got[:5], expected, rtol=1e-17)

    def test_modulo_operation(self):
        """
        Method for testing the modulo operation. Mainly tests part not covered
        by the doctests.
        """
        tr = Trace(data=np.arange(25))
        # Wrong type raises.
        self.assertRaises(TypeError, tr.__mod__, 5.0)
        self.assertRaises(TypeError, tr.__mod__, "123")
        # Needs to be a positive integer.
        self.assertRaises(ValueError, tr.__mod__, 0)
        self.assertRaises(ValueError, tr.__mod__, -11)
        # If num is more then the number of samples, a copy will be returned.
        st = tr % 500
        self.assertEqual(tr, st[0])
        self.assertEqual(len(st), 1)
        self.assertFalse(tr.data is st[0].data)

    def test_plot(self):
        """
        Tests plot method if matplotlib is installed
        """
        tr = Trace(data=np.arange(25))
        tr.plot(show=False)

    def test_spectrogram(self):
        """
        Tests spectrogram method if matplotlib is installed
        """
        tr = Trace(data=np.arange(25))
        tr.stats.sampling_rate = 20
        tr.spectrogram(show=False)

    def test_raise_masked(self):
        """
        Tests that detrend() raises in case of a masked array. (see #498)
        """
        x = np.arange(10)
        x = np.ma.masked_inside(x, 3, 4)
        tr = Trace(x)
        self.assertRaises(NotImplementedError, tr.detrend)

    def test_split(self):
        """
        Tests split method of the Trace class.
        """
        # set up
        tr1 = Trace(data=np.arange(1000))
        tr1.stats.sampling_rate = 200
        start = UTCDateTime(2000, 1, 1, 0, 0, 0, 0)
        tr1.stats.starttime = start
        tr2 = Trace(data=np.arange(0, 1000)[::-1])
        tr2.stats.sampling_rate = 200
        tr2.stats.starttime = start + 10
        # add will create new trace with masked array
        trace = tr1 + tr2
        self.assertTrue(isinstance(trace.data, np.ma.masked_array))
        # split
        self.assertTrue(isinstance(trace, Trace))
        st = trace.split()
        self.assertTrue(isinstance(st, Stream))
        self.assertEqual(len(st[0]), 1000)
        self.assertEqual(len(st[1]), 1000)
        # check if have no masked arrays
        self.assertFalse(isinstance(st[0].data, np.ma.masked_array))
        self.assertFalse(isinstance(st[1].data, np.ma.masked_array))

    def test_split_empty_masked_array(self):
        """
        Test split method with a masked array without any data.
        """
        tr = Trace(data=np.ma.masked_all(100))

        self.assertTrue(isinstance(tr.data, np.ma.masked_array))
        self.assertTrue(isinstance(tr, Trace))

        st = tr.split()

        self.assertTrue(isinstance(st, Stream))
        self.assertEqual(len(st), 0)

    def test_split_masked_array_without_actually_masked_values(self):
        """
        Tests splitting a masked array without actually masked data.
        """
        # First non masked.
        tr = Trace(data=np.arange(100))
        st = tr.copy().split()
        self.assertEqual(len(st), 1)
        self.assertEqual(tr, st[0])
        self.assertFalse(isinstance(st[0].data, np.ma.masked_array))

        # Now the same thing but with an initially masked array but no
        # masked values.
        tr = Trace(data=np.ma.arange(100))
        self.assertFalse(tr.data.mask)
        st = tr.copy().split()
        self.assertEqual(len(st), 1)
        self.assertEqual(tr, st[0])
        self.assertFalse(isinstance(st[0].data, np.ma.masked_array))

    def test_simulate_evalresp(self):
        """
        Tests that trace.simulate calls evalresp with the correct network,
        station, location and channel information.
        """
        tr = read()[0]

        # Wrap in try/except as it of course will fail because the mocked
        # function returns None.
        try:
            with mock.patch("obspy.signal.invsim.evalresp") as patch:
                tr.simulate(seedresp={"filename": "RESP.dummy",
                                      "units": "VEL",
                                      "date": tr.stats.starttime})
        except Exception:
            pass

        self.assertEqual(patch.call_count, 1)
        _, kwargs = patch.call_args

        # Make sure that every item of the trace is passed to the evalresp
        # function.
        for key in ["network", "station", "location", "channel"]:
            self.assertEqual(
                kwargs[key if key != "location" else "locid"], tr.stats[key],
                msg="'%s' did not get passed on to evalresp" % key)

    def test_issue_540(self):
        """
        Trim with pad=True and given fill value should not return a masked
        NumPy array.
        """
        # fill_value = None
        tr = read()[0]
        self.assertEqual(len(tr), 3000)
        tr.trim(starttime=tr.stats.starttime - 0.01,
                endtime=tr.stats.endtime + 0.01, pad=True, fill_value=None)
        self.assertEqual(len(tr), 3002)
        self.assertTrue(isinstance(tr.data, np.ma.masked_array))
        self.assertIs(tr.data[0], np.ma.masked)
        self.assertTrue(tr.data[1] is not np.ma.masked)
        self.assertTrue(tr.data[-2] is not np.ma.masked)
        self.assertIs(tr.data[-1], np.ma.masked)
        # fill_value = 999
        tr = read()[0]
        self.assertEqual(len(tr), 3000)
        tr.trim(starttime=tr.stats.starttime - 0.01,
                endtime=tr.stats.endtime + 0.01, pad=True, fill_value=999)
        self.assertEqual(len(tr), 3002)
        self.assertFalse(isinstance(tr.data, np.ma.masked_array))
        self.assertEqual(tr.data[0], 999)
        self.assertEqual(tr.data[-1], 999)
        # given fill_value but actually no padding at all
        tr = read()[0]
        self.assertEqual(len(tr), 3000)
        tr.trim(starttime=tr.stats.starttime,
                endtime=tr.stats.endtime, pad=True, fill_value=-999)
        self.assertEqual(len(tr), 3000)
        self.assertFalse(isinstance(tr.data, np.ma.masked_array))

    def test_resample(self):
        """
        Tests the resampling of traces.
        """
        tr = read()[0]

        self.assertEqual(tr.stats.sampling_rate, 100.0)
        self.assertEqual(tr.stats.npts, 3000)

        tr_2 = tr.copy().resample(sampling_rate=50.0)
        self.assertEqual(tr_2.stats.endtime, tr.stats.endtime - 1.0 / 100.0)
        self.assertEqual(tr_2.stats.sampling_rate, 50.0)
        self.assertEqual(tr_2.stats.starttime, tr.stats.starttime)

        tr_3 = tr.copy().resample(sampling_rate=10.0)
        self.assertEqual(tr_3.stats.endtime, tr.stats.endtime - 9.0 / 100.0)
        self.assertEqual(tr_3.stats.sampling_rate, 10.0)
        self.assertEqual(tr_3.stats.starttime, tr.stats.starttime)

        tr_4 = tr.copy()
        tr_4.data = np.require(tr_4.data,
                               dtype=tr_4.data.dtype.newbyteorder('>'))
        tr_4 = tr_4.resample(sampling_rate=10.0)
        self.assertEqual(tr_4.stats.endtime, tr.stats.endtime - 9.0 / 100.0)
        self.assertEqual(tr_4.stats.sampling_rate, 10.0)
        self.assertEqual(tr_4.stats.starttime, tr.stats.starttime)

    def test_method_chaining(self):
        """
        Tests that method chaining works for all methods on the Trace object
        where it is sensible.
        """
        # This essentially just checks that the methods are chainable. The
        # methods are tested elsewhere and a full test would be a lot of work
        # with questionable return.
        tr = read()[0]
        temp_tr = tr.trim(tr.stats.starttime + 1)\
            .verify()\
            .filter("lowpass", freq=2.0)\
            .simulate(paz_remove={'poles': [-0.037004 + 0.037016j,
                                            -0.037004 - 0.037016j,
                                            -251.33 + 0j],
                                  'zeros': [0j, 0j],
                                  'gain': 60077000.0,
                                  'sensitivity': 2516778400.0})\
            .trigger(type="zdetect", nsta=20)\
            .decimate(factor=2, no_filter=True)\
            .resample(tr.stats.sampling_rate / 2.0)\
            .differentiate()\
            .integrate()\
            .detrend()\
            .taper(max_percentage=0.05, type='cosine')\
            .normalize()
        self.assertIs(temp_tr, tr)
        self.assertTrue(isinstance(tr, Trace))
        self.assertGreater(tr.stats.npts, 0)

        # Use the processing chain to check the results. The trim() methods
        # does not have an entry in the processing chain.
        pr = tr.stats.processing
        self.assertIn("trim", pr[0])
        self.assertTrue("filter" in pr[1] and "lowpass" in pr[1])
        self.assertIn("simulate", pr[2])
        self.assertIn("trigger", pr[3])
        self.assertIn("decimate", pr[4])
        self.assertIn("resample", pr[5])
        self.assertIn("differentiate", pr[6])
        self.assertIn("integrate", pr[7])
        self.assertIn("detrend", pr[8])
        self.assertIn("taper", pr[9])
        self.assertIn("normalize", pr[10])

    def test_skip_empty_trace(self):
        tr = read()[0]
        t = tr.stats.endtime + 10
        tr.trim(t, t + 10)
        tr.detrend()
        tr.resample(400)
        tr.differentiate()
        tr.integrate()
        tr.taper(max_percentage=0.1)

    def test_issue_695(self):
        x = np.zeros(12)
        data = [x.reshape((12, 1)),
                x.reshape((1, 12)),
                x.reshape((2, 6)),
                x.reshape((6, 2)),
                x.reshape((2, 2, 3)),
                x.reshape((1, 2, 2, 3)),
                x[0][()],  # 0-dim array
                ]
        for d in data:
            self.assertRaises(ValueError, Trace, data=d)

    def test_remove_response(self):
        """
        Test remove_response() method against simulate() with equivalent
        parameters to check response removal from Response object read from
        StationXML against pure evalresp providing an external RESP file.
        """
        tr1 = read()[0]
        tr2 = tr1.copy()
        # deconvolve from dataless with simulate() via Parser from
        # dataless/RESP
        parser = Parser("/path/to/dataless.seed.BW_RJOB")
        tr1.simulate(seedresp={"filename": parser, "units": "VEL"},
                     water_level=60, pre_filt=(0.1, 0.5, 30, 50), sacsim=True,
                     pitsasim=False)
        # deconvolve from StationXML with remove_response()
        tr2.remove_response(pre_filt=(0.1, 0.5, 30, 50))
        np.testing.assert_array_almost_equal(tr1.data, tr2.data)

    def test_remove_polynomial_response(self):
        """
        """
        from obspy import read_inventory
        path = os.path.dirname(__file__)

        # blockette 62, stage 0
        tr = read()[0]
        tr.stats.network = 'IU'
        tr.stats.station = 'ANTO'
        tr.stats.location = '30'
        tr.stats.channel = 'LDO'
        tr.stats.starttime = UTCDateTime("2010-07-23T00:00:00")
        # remove response
        del tr.stats.response
        filename = os.path.join(path, 'data', 'stationxml_IU.ANTO.30.LDO.xml')
        inv = read_inventory(filename, format='StationXML')
        tr.attach_response(inv)
        tr.remove_response()

        # blockette 62, stage 1 + blockette 58, stage 2
        tr = read()[0]
        tr.stats.network = 'BK'
        tr.stats.station = 'CMB'
        tr.stats.location = ''
        tr.stats.channel = 'LKS'
        tr.stats.starttime = UTCDateTime("2004-06-16T00:00:00")
        # remove response
        del tr.stats.response
        filename = os.path.join(path, 'data', 'stationxml_BK.CMB.__.LKS.xml')
        inv = read_inventory(filename, format='StationXML')
        tr.attach_response(inv)
        # raises UserWarning: Stage gain not defined - ignoring
        with warnings.catch_warnings(record=True):
            warnings.simplefilter("ignore", UserWarning)
            tr.remove_response()

    def test_processing_info_remove_response_and_sensitivity(self):
        """
        Tests adding processing info for remove_response() and
        remove_sensitivity().

        See #1247.
        """
        # remove_sensitivity() with response object attached to the trace.
        tr = read()[0]
        self.assertNotIn("processing", tr.stats)
        tr.remove_sensitivity()
        self.assertIn("processing", tr.stats)
        self.assertEqual(len(tr.stats.processing), 1)
        self.assertTrue(tr.stats.processing[0].endswith(
            "remove_sensitivity(inventory=None)"))

        # With passed inventory object.
        tr = read()[0]
        self.assertNotIn("processing", tr.stats)
        tr.remove_sensitivity(inventory=read_inventory())
        self.assertIn("processing", tr.stats)
        self.assertEqual(len(tr.stats.processing), 1)
        self.assertIn("remove_sensitivity(inventory=<obspy.core.inventory."
                      "inventory.Inventory object ", tr.stats.processing[0])

        # remove_response()
        tr = read()[0]
        self.assertNotIn("processing", tr.stats)
        tr.remove_response()
        self.assertIn("processing", tr.stats)
        self.assertEqual(len(tr.stats.processing), 1)
        self.assertIn("remove_response(", tr.stats.processing[0])
        self.assertIn("inventory=None", tr.stats.processing[0])

        # With passed inventory object.
        tr = read()[0]
        self.assertNotIn("processing", tr.stats)
        tr.remove_response(inventory=read_inventory())
        self.assertIn("processing", tr.stats)
        self.assertEqual(len(tr.stats.processing), 1)
        self.assertIn("remove_response(", tr.stats.processing[0])
        self.assertIn("inventory=<obspy.core.inventory.inventory.Inventory "
                      "object", tr.stats.processing[0])

    def test_processing_information(self):
        """
        Test case for the automatic processing information.
        """
        tr = read()[0]
        trimming_starttime = tr.stats.starttime + 1
        tr.trim(trimming_starttime)
        tr.filter("lowpass", freq=2.0)
        tr.simulate(paz_remove={
            'poles': [-0.037004 + 0.037016j, -0.037004 - 0.037016j,
                      -251.33 + 0j],
            'zeros': [0j, 0j],
            'gain': 60077000.0,
            'sensitivity': 2516778400.0})
        tr.trigger(type="zdetect", nsta=20)
        tr.decimate(factor=2, no_filter=True)
        tr.resample(tr.stats.sampling_rate / 2.0)
        tr.differentiate()
        tr.integrate()
        tr.detrend()
        tr.taper(max_percentage=0.05, type='cosine')
        tr.normalize()

        pr = tr.stats.processing

        self.assertIn("trim", pr[0])
        self.assertEqual(
            "ObsPy %s: trim(endtime=None::fill_value=None::"
            "nearest_sample=True::pad=False::starttime=%s)" % (
                __version__, repr(trimming_starttime)),
            pr[0])
        self.assertIn("filter", pr[1])
        self.assertIn("simulate", pr[2])
        self.assertIn("trigger", pr[3])
        self.assertIn("decimate", pr[4])
        self.assertIn("resample", pr[5])
        self.assertIn("differentiate", pr[6])
        self.assertIn("integrate", pr[7])
        self.assertIn("detrend", pr[8])
        self.assertIn("taper", pr[9])
        self.assertIn("normalize", pr[10])

    def test_no_processing_info_for_failed_operations(self):
        """
        If an operation fails, no processing information should be attached
        to the Trace object.
        """
        # create test Trace
        tr = Trace(data=np.arange(20))
        self.assertFalse("processing" in tr.stats)
        # This decimation by a factor of 7 in this case would change the
        # end time of the time series. Therefore it fails.
        self.assertRaises(ValueError, tr.decimate, 7, strict_length=True)
        # No processing should be applied yet.
        self.assertFalse("processing" in tr.stats)

        # Test the same but this time with an already existing processing
        # information.
        tr = Trace(data=np.arange(20))
        tr.detrend()
        self.assertEqual(len(tr.stats.processing), 1)
        info = tr.stats.processing[0]

        self.assertRaises(ValueError, tr.decimate, 7, strict_length=True)
        self.assertEqual(tr.stats.processing, [info])

    def test_meta(self):
        """
        Tests Trace.meta an alternative to Trace.stats
        """
        tr = Trace()
        tr.meta = Stats({'network': 'NW'})
        self.assertEqual(tr.stats.network, 'NW')
        tr.stats = Stats({'network': 'BW'})
        self.assertEqual(tr.meta.network, 'BW')

    def test_interpolate(self):
        """
        Tests the interpolate function.

        This also tests the interpolation in obspy.signal. No need to repeat
        the same test twice I guess.
        """
        # Load the prepared data. The data has been created using SAC.
        file_ = "interpolation_test_random_waveform_delta_0.01_npts_50.sac"
        org_tr = read("/path/to/%s" % file_)[0]
        file_ = "interpolation_test_interpolated_delta_0.003.sac"
        interp_delta_0_003 = read("/path/to/%s" % file_)[0]
        file_ = "interpolation_test_interpolated_delta_0.077.sac"
        interp_delta_0_077 = read("/path/to/%s" % file_)[0]

        # Perform the same interpolation as in Python with ObsPy.
        int_tr = org_tr.copy().interpolate(sampling_rate=1.0 / 0.003,
                                           method="weighted_average_slopes")
        # Assert that the sampling rate has been set correctly.
        self.assertEqual(int_tr.stats.delta, 0.003)
        # Assert that the new end time is smaller than the old one. SAC at
        # times performs some extrapolation which we do not want to do here.
        self.assertLessEqual(int_tr.stats.endtime, org_tr.stats.endtime)
        # SAC extrapolates a bit which we don't want here. The deviations
        # to SAC are likely due to the fact that we use double precision
        # math while SAC uses single precision math.
        self.assertTrue(np.allclose(
            int_tr.data,
            interp_delta_0_003.data[:int_tr.stats.npts],
            rtol=1E-3))

        int_tr = org_tr.copy().interpolate(sampling_rate=1.0 / 0.077,
                                           method="weighted_average_slopes")
        # Assert that the sampling rate has been set correctly.
        self.assertEqual(int_tr.stats.delta, 0.077)
        # Assert that the new end time is smaller than the old one. SAC
        # calculates one sample less in this case.
        self.assertLessEqual(int_tr.stats.endtime, org_tr.stats.endtime)
        self.assertTrue(np.allclose(
            int_tr.data[:interp_delta_0_077.stats.npts],
            interp_delta_0_077.data,
            rtol=1E-5))

        # Also test the other interpolation methods mainly by assuring the
        # correct SciPy function is called and everything stays internally
        # consistent. SciPy's functions are tested enough to be sure that
        # they work.
        for inter_type in ["linear", "nearest", "zero"]:
            with mock.patch("scipy.interpolate.interp1d") as patch:
                patch.return_value = lambda x: x
                org_tr.copy().interpolate(sampling_rate=0.5, method=inter_type)
            self.assertEqual(patch.call_count, 1)
            self.assertEqual(patch.call_args[1]["kind"], inter_type)

            int_tr = org_tr.copy().interpolate(sampling_rate=0.5,
                                               method=inter_type)
            self.assertEqual(int_tr.stats.delta, 2.0)
            self.assertLessEqual(int_tr.stats.endtime, org_tr.stats.endtime)

        for inter_type in ["slinear", "quadratic", "cubic", 1, 2, 3]:
            with mock.patch("scipy.interpolate.InterpolatedUnivariateSpline") \
                    as patch:
                patch.return_value = lambda x: x
                org_tr.copy().interpolate(sampling_rate=0.5, method=inter_type)
            s_map = {
                "slinear": 1,
                "quadratic": 2,
                "cubic": 3
            }
            if inter_type in s_map:
                inter_type = s_map[inter_type]
            self.assertEqual(patch.call_count, 1)
            self.assertEqual(patch.call_args[1]["k"], inter_type)

            int_tr = org_tr.copy().interpolate(sampling_rate=0.5,
                                               method=inter_type)
            self.assertEqual(int_tr.stats.delta, 2.0)
            self.assertLessEqual(int_tr.stats.endtime, org_tr.stats.endtime)

    def test_interpolation_time_shift(self):
        """
        Tests the time shift of the interpolation.
        """
        tr = read()[0]
        tr.stats.sampling_rate = 1.0
        tr.data = tr.data[:500]
        tr.interpolate(method="lanczos", sampling_rate=10.0, a=20)
        tr.stats.sampling_rate = 1.0
        tr.data = tr.data[:500]
        tr.stats.starttime = UTCDateTime(0)

        org_tr = tr.copy()

        # Now this does not do much for now but actually just shifts the
        # samples.
        tr.interpolate(method="lanczos", sampling_rate=1.0, a=1,
                       time_shift=0.2)
        self.assertEqual(tr.stats.starttime, org_tr.stats.starttime + 0.2)
        self.assertEqual(tr.stats.endtime, org_tr.stats.endtime + 0.2)
        np.testing.assert_allclose(tr.data, org_tr.data, atol=1E-9)

        tr.interpolate(method="lanczos", sampling_rate=1.0, a=1,
                       time_shift=0.4)
        self.assertEqual(tr.stats.starttime, org_tr.stats.starttime + 0.6)
        self.assertEqual(tr.stats.endtime, org_tr.stats.endtime + 0.6)
        np.testing.assert_allclose(tr.data, org_tr.data, atol=1E-9)

        tr.interpolate(method="lanczos", sampling_rate=1.0, a=1,
                       time_shift=-0.6)
        self.assertEqual(tr.stats.starttime, org_tr.stats.starttime)
        self.assertEqual(tr.stats.endtime, org_tr.stats.endtime)
        np.testing.assert_allclose(tr.data, org_tr.data, atol=1E-9)

        # This becomes more interesting when also fixing the sample
        # positions. Then one can shift by subsample accuracy while leaving
        # the sample positions intact. Note that there naturally are some
        # boundary effects and as the interpolation method does not deal
        # with any kind of extrapolation you will lose the first or last
        # samples.
        # This is a fairly extreme example but of course there are errors
        # when doing an interpolation - a shift using an FFT is more accurate.
        tr.interpolate(method="lanczos", sampling_rate=1.0, a=50,
                       starttime=tr.stats.starttime + tr.stats.delta,
                       time_shift=0.2)
        # The sample point did not change but we lost the first sample,
        # as we shifted towards the future.
        self.assertEqual(tr.stats.starttime, org_tr.stats.starttime + 1.0)
        self.assertEqual(tr.stats.endtime, org_tr.stats.endtime)
        # The data naturally also changed.
        self.assertRaises(AssertionError, np.testing.assert_allclose,
                          tr.data, org_tr.data[1:], atol=1E-9)
        # Shift back. This time we will lose the last sample.
        tr.interpolate(method="lanczos", sampling_rate=1.0, a=50,
                       starttime=tr.stats.starttime,
                       time_shift=-0.2)
        self.assertEqual(tr.stats.starttime, org_tr.stats.starttime + 1.0)
        self.assertEqual(tr.stats.endtime, org_tr.stats.endtime - 1.0)
        # But the data (aside from edge effects - we are going forward and
        # backwards again so they go twice as far!) should now again be the
        # same as we started out with.
        np.testing.assert_allclose(
            tr.data[100:-100], org_tr.data[101:-101], atol=1E-9, rtol=1E-4)

    def test_interpolation_arguments(self):
        """
        Test case for the interpolation arguments.
        """
        tr = read()[0]
        tr.stats.sampling_rate = 1.0
        tr.data = tr.data[:50]

        for inter_type in ["linear", "nearest", "zero", "slinear",
                           "quadratic", "cubic", 1, 2, 3,
                           "weighted_average_slopes"]:
            # If only the sampling rate is specified, the end time will be very
            # close to the original end time but never bigger.
            interp_tr = tr.copy().interpolate(sampling_rate=0.3,
                                              method=inter_type)
            self.assertEqual(tr.stats.starttime, interp_tr.stats.starttime)
            self.assertTrue(tr.stats.endtime >= interp_tr.stats.endtime >=
                            tr.stats.endtime - (1.0 / 0.3))

            # If the starttime is modified the new starttime will be used but
            # the end time will again be modified as little as possible.
            interp_tr = tr.copy().interpolate(sampling_rate=0.3,
                                              method=inter_type,
                                              starttime=tr.stats.starttime +
                                              5.0)
            self.assertEqual(tr.stats.starttime + 5.0,
                             interp_tr.stats.starttime)
            self.assertTrue(tr.stats.endtime >= interp_tr.stats.endtime >=
                            tr.stats.endtime - (1.0 / 0.3))

            # If npts is given it will be used to modify the end time.
            interp_tr = tr.copy().interpolate(sampling_rate=0.3,
                                              method=inter_type, npts=10)
            self.assertEqual(tr.stats.starttime,
                             interp_tr.stats.starttime)
            self.assertEqual(interp_tr.stats.npts, 10)

            # If npts and starttime are given, both will be modified.
            interp_tr = tr.copy().interpolate(sampling_rate=0.3,
                                              method=inter_type,
                                              starttime=tr.stats.starttime +
                                              5.0, npts=10)
            self.assertEqual(tr.stats.starttime + 5.0,
                             interp_tr.stats.starttime)
            self.assertEqual(interp_tr.stats.npts, 10)

            # An earlier starttime will raise an exception. No extrapolation
            # is supported
            self.assertRaises(ValueError, tr.copy().interpolate,
                              sampling_rate=1.0,
                              starttime=tr.stats.starttime - 10.0)
            # As will too many samples that would overstep the end time bound.
            self.assertRaises(ValueError, tr.copy().interpolate,
                              sampling_rate=1.0,
                              npts=tr.stats.npts * 1E6)

            # A negative or zero desired sampling rate should raise.
            self.assertRaises(ValueError, tr.copy().interpolate,
                              sampling_rate=0.0)
            self.assertRaises(ValueError, tr.copy().interpolate,
                              sampling_rate=-1.0)

    def test_resample_new(self):
        """
        Tests if Trace.resample works as expected and test that issue #857 is
        resolved.
        """
        starttime = UTCDateTime("1970-01-01T00:00:00.000000Z")
        tr0 = Trace(np.sin(np.linspace(0, 2 * np.pi, 10)),
                    {'sampling_rate': 1.0,
                     'starttime': starttime})
        # downsample
        tr = tr0.copy()
        tr.resample(0.5, window='hanning', no_filter=True)
        self.assertEqual(len(tr.data), 5)
        expected = np.array([0.19478735, 0.83618307, 0.32200221,
                             -0.7794053, -0.57356732])
        self.assertTrue(np.all(np.abs(tr.data - expected) < 1e-7))
        self.assertEqual(tr.stats.sampling_rate, 0.5)
        self.assertEqual(tr.stats.delta, 2.0)
        self.assertEqual(tr.stats.npts, 5)
        self.assertEqual(tr.stats.starttime, starttime)
        self.assertEqual(tr.stats.endtime,
                         starttime + tr.stats.delta * (tr.stats.npts - 1))

        # upsample
        tr = tr0.copy()
        tr.resample(2.0, window='hanning', no_filter=True)
        self.assertEqual(len(tr.data), 20)
        self.assertEqual(tr.stats.sampling_rate, 2.0)
        self.assertEqual(tr.stats.delta, 0.5)
        self.assertEqual(tr.stats.npts, 20)
        self.assertEqual(tr.stats.starttime, starttime)
        self.assertEqual(tr.stats.endtime,
                         starttime + tr.stats.delta * (tr.stats.npts - 1))

        # downsample with non integer ratio
        tr = tr0.copy()
        tr.resample(0.75, window='hanning', no_filter=True)
        self.assertEqual(len(tr.data), int(10 * .75))
        expected = np.array([0.15425413, 0.66991128, 0.74610418, 0.11960477,
                             -0.60644662, -0.77403839, -0.30938935])
        self.assertTrue(np.all(np.abs(tr.data - expected) < 1e-7))
        self.assertEqual(tr.stats.sampling_rate, 0.75)
        self.assertEqual(tr.stats.delta, 1 / 0.75)
        self.assertEqual(tr.stats.npts, int(10 * .75))
        self.assertEqual(tr.stats.starttime, starttime)
        self.assertEqual(tr.stats.endtime,
                         starttime + tr.stats.delta * (tr.stats.npts - 1))

        # downsample without window
        tr = tr0.copy()
        tr.resample(0.5, window=None, no_filter=True)
        self.assertEqual(len(tr.data), 5)
        self.assertEqual(tr.stats.sampling_rate, 0.5)
        self.assertEqual(tr.stats.delta, 2.0)
        self.assertEqual(tr.stats.npts, 5)
        self.assertEqual(tr.stats.starttime, starttime)
        self.assertEqual(tr.stats.endtime,
                         starttime + tr.stats.delta * (tr.stats.npts - 1))

        # downsample with window and automatic filtering
        tr = tr0.copy()
        tr.resample(0.5, window='hanning', no_filter=False)
        self.assertEqual(len(tr.data), 5)
        self.assertEqual(tr.stats.sampling_rate, 0.5)
        self.assertEqual(tr.stats.delta, 2.0)
        self.assertEqual(tr.stats.npts, 5)
        self.assertEqual(tr.stats.starttime, starttime)
        self.assertEqual(tr.stats.endtime,
                         starttime + tr.stats.delta * (tr.stats.npts - 1))

        # downsample with custom window
        tr = tr0.copy()
        window = np.ones((tr.stats.npts))
        tr.resample(0.5, window=window, no_filter=True)

        # downsample with bad window
        tr = tr0.copy()
        window = np.array([0, 1, 2, 3])
        self.assertRaises(ValueError, tr.resample,
                          sampling_rate=0.5, window=window, no_filter=True)

    def test_slide(self):
        """
        Tests for sliding a window across a trace object.
        """
        tr = Trace(data=np.linspace(0, 100, 101))
        tr.stats.starttime = UTCDateTime(0.0)
        tr.stats.sampling_rate = 5.0

        # First slice it in 4 pieces. Window length is in seconds.
        slices = []
        for window_tr in tr.slide(window_length=5.0, step=5.0):
            slices.append(window_tr)

        self.assertEqual(len(slices), 4)
        self.assertEqual(slices[0],
                         tr.slice(UTCDateTime(0), UTCDateTime(5)))
        self.assertEqual(slices[1],
                         tr.slice(UTCDateTime(5), UTCDateTime(10)))
        self.assertEqual(slices[2],
                         tr.slice(UTCDateTime(10), UTCDateTime(15)))
        self.assertEqual(slices[3],
                         tr.slice(UTCDateTime(15), UTCDateTime(20)))

        # Different step which is the distance between two windows measured
        # from the start of the first window in seconds.
        slices = []
        for window_tr in tr.slide(window_length=5.0, step=10.0):
            slices.append(window_tr)

        self.assertEqual(len(slices), 2)
        self.assertEqual(slices[0],
                         tr.slice(UTCDateTime(0), UTCDateTime(5)))
        self.assertEqual(slices[1],
                         tr.slice(UTCDateTime(10), UTCDateTime(15)))

        # Offset determines the initial starting point. It defaults to zero.
        slices = []
        for window_tr in tr.slide(window_length=5.0, step=6.5, offset=8.5):
            slices.append(window_tr)

        self.assertEqual(len(slices), 2)
        self.assertEqual(slices[0],
                         tr.slice(UTCDateTime(8.5), UTCDateTime(13.5)))
        self.assertEqual(slices[1],
                         tr.slice(UTCDateTime(15.0), UTCDateTime(20.0)))

        # By default only full length windows will be returned so any
        # remainder that can no longer make up a full window will not be
        # returned.
        slices = []
        for window_tr in tr.slide(window_length=15.0, step=15.0):
            slices.append(window_tr)

        self.assertEqual(len(slices), 1)
        self.assertEqual(slices[0],
                         tr.slice(UTCDateTime(0.0), UTCDateTime(15.0)))

        # But it can optionally be returned.
        slices = []
        for window_tr in tr.slide(window_length=15.0, step=15.0,
                                  include_partial_windows=True):
            slices.append(window_tr)

        self.assertEqual(len(slices), 2)
        self.assertEqual(slices[0],
                         tr.slice(UTCDateTime(0.0), UTCDateTime(15.0)))
        self.assertEqual(slices[1],
                         tr.slice(UTCDateTime(15.0), UTCDateTime(20.0)))

        # Negative step lengths work together with an offset.
        slices = []
        for window_tr in tr.slide(window_length=5.0, step=-5.0, offset=20.0):
            slices.append(window_tr)

        self.assertEqual(len(slices), 4)
        self.assertEqual(slices[0],
                         tr.slice(UTCDateTime(15), UTCDateTime(20)))
        self.assertEqual(slices[1],
                         tr.slice(UTCDateTime(10), UTCDateTime(15)))
        self.assertEqual(slices[2],
                         tr.slice(UTCDateTime(5), UTCDateTime(10)))
        self.assertEqual(slices[3],
                         tr.slice(UTCDateTime(0), UTCDateTime(5)))

    def test_slide_nearest_sample(self):
        """
        Tests that the nearest_sample argument is correctly passed to the
        slice function calls.
        """
        tr = Trace(data=np.linspace(0, 100, 101))
        tr.stats.starttime = UTCDateTime(0.0)
        tr.stats.sampling_rate = 5.0

        # It defaults to True.
        with mock.patch("obspy.core.trace.Trace.slice") as patch:
            patch.return_value = tr
            list(tr.slide(5, 5))

        self.assertEqual(patch.call_count, 4)
        for arg in patch.call_args_list:
            self.assertTrue(arg[1]["nearest_sample"])

        # Force True.
        with mock.patch("obspy.core.trace.Trace.slice") as patch:
            patch.return_value = tr
            list(tr.slide(5, 5, nearest_sample=True))

        self.assertEqual(patch.call_count, 4)
        for arg in patch.call_args_list:
            self.assertTrue(arg[1]["nearest_sample"])

        # Set to False.
        with mock.patch("obspy.core.trace.Trace.slice") as patch:
            patch.return_value = tr
            list(tr.slide(5, 5, nearest_sample=False))

        self.assertEqual(patch.call_count, 4)
        for arg in patch.call_args_list:
            self.assertFalse(arg[1]["nearest_sample"])

    def test_remove_response_plot(self):
        """
        Tests the plotting option of remove_response().
        """
        tr = read("/path/to/IU_ULN_00_LH1_2015-07-18T02.mseed")[0]
        inv = read_inventory("/path/to/IU_ULN_00_LH1.xml")
        tr.attach_response(inv)

        pre_filt = [0.001, 0.005, 10, 20]

        image_dir = os.path.join(os.path.dirname(__file__), 'images')
        with ImageComparison(image_dir, "trace_remove_response.png",
                             reltol=1.5) as ic:
            tr.remove_response(pre_filt=pre_filt, output="DISP",
                               water_level=60, end_stage=None, plot=ic.name)

    def test_normalize(self):
        """
        Tests the normalize() method on normal and edge cases.
        """
        # Nothing should happen with ones.
        tr = Trace(data=np.ones(5))
        tr.normalize()
        np.testing.assert_allclose(tr.data, np.ones(5))

        # 10s should be normalized to all ones.
        tr = Trace(data=10 * np.ones(5))
        tr.normalize()
        np.testing.assert_allclose(tr.data, np.ones(5))

        # Negative 10s should be normalized to negative ones.
        tr = Trace(data=-10 * np.ones(5))
        tr.normalize()
        np.testing.assert_allclose(tr.data, -np.ones(5))

        # 10s and a couple of 5s should be normalized to 1s and a couple of
        # 0.5s.
        tr = Trace(data=np.array([10.0, 10.0, 5.0, 5.0]))
        tr.normalize()
        np.testing.assert_allclose(tr.data, np.array([1.0, 1.0, 0.5, 0.5]))

        # Same but negative values.
        tr = Trace(data=np.array([-10.0, -10.0, -5.0, -5.0]))
        tr.normalize()
        np.testing.assert_allclose(tr.data, np.array([-1.0, -1.0, -0.5, -0.5]))

        # Mixed values.
        tr = Trace(data=np.array([-10.0, -10.0, 5.0, 5.0]))
        tr.normalize()
        np.testing.assert_allclose(tr.data, np.array([-1.0, -1.0, 0.5, 0.5]))

        # Mixed values.
        tr = Trace(data=np.array([-10.0, 10.0, -5.0, 5.0]))
        tr.normalize()
        np.testing.assert_allclose(tr.data, np.array([-1.0, 1.0, -0.5, 0.5]))

        # Mixed values.
        tr = Trace(data=np.array([-10.0, -10.0, 0.0, 0.0]))
        tr.normalize()
        np.testing.assert_allclose(tr.data, np.array([-1.0, -1.0, 0.0, 0.0]))

        # Mixed values.
        tr = Trace(data=np.array([10.0, 10.0, 0.0, 0.0]))
        tr.normalize()
        np.testing.assert_allclose(tr.data, np.array([1.0, 1.0, 0.0, 0.0]))

        # Small values get larger.
        tr = Trace(data=np.array([-0.5, 0.5, 0.1, -0.1]))
        tr.normalize()
        np.testing.assert_allclose(tr.data, np.array([-1.0, 1.0, 0.2, -0.2]))

        # All zeros. Nothing should happen but a warning will be raised.
        tr = Trace(data=np.array([-0.0, 0.0, 0.0, -0.0]))
        with warnings.catch_warnings(record=True) as w:
            warnings.simplefilter("always")
            tr.normalize()
        self.assertEqual(w[0].category, UserWarning)
        self.assertIn("Attempting to normalize by dividing through zero.",
                      w[0].message.args[0])
        np.testing.assert_allclose(tr.data, np.array([-0.0, 0.0, 0.0, -0.0]))

        # Passing the norm specifies the division factor.
        tr = Trace(data=np.array([10.0, 10.0, 0.0, 0.0]))
        tr.normalize(norm=2)
        np.testing.assert_allclose(tr.data, np.array([5.0, 5.0, 0.0, 0.0]))

        # Passing the norm specifies the division factor. Nothing happens
        # with zero.
        tr = Trace(data=np.array([10.0, 10.0, 0.0, 0.0]))
        with warnings.catch_warnings(record=True) as w:
            warnings.simplefilter("always")
            tr.normalize(norm=0)
        self.assertEqual(w[0].category, UserWarning)
        self.assertIn("Attempting to normalize by dividing through zero.",
                      w[0].message.args[0])
        np.testing.assert_allclose(tr.data, np.array([10.0, 10.0, 0.0, 0.0]))

        # Warning is raised for a negative norm, but the positive value is
        # used.
        tr = Trace(data=np.array([10.0, 10.0, 0.0, 0.0]))
        with warnings.catch_warnings(record=True) as w:
            warnings.simplefilter("always")
            tr.normalize(norm=-2)

        self.assertEqual(w[0].category, UserWarning)
        self.assertIn("Normalizing with negative values is forbidden.",
                      w[0].message.args[0])

        np.testing.assert_allclose(tr.data, np.array([5.0, 5.0, 0.0, 0.0]))

    def test_dtype_is_not_unnecessarily_changed(self):
        """
        The dtype of the data should not change if not necessary. In general
        this means that a float32 array should not become a float64 array
        and vice-versa. Integer arrays will always be upcasted to float64
        arrays when integer output makes no sense. Not all int32 numbers can be
        accurately represented by float32 arrays so double precision is
        required in order to not lose accuracy.

        Exceptions are custom coded C routines where we usually opt to only
        include either a single or a double precision version.
        """
        tr = read()[0]
        tr.data = tr.data[:100]

        # One for each common input dtype.
        tr_int32 = tr.copy()
        tr_int32.data = np.require(tr_int32.data, dtype=np.int32)
        tr_int64 = tr.copy()
        tr_int64.data = np.require(tr_int64.data, dtype=np.int64)
        tr_float32 = tr.copy()
        tr_float32.data = np.require(tr_float32.data, dtype=np.float32)
        tr_float64 = tr.copy()
        tr_float64.data = np.require(tr_float64.data, dtype=np.float64)

        # Trimming.
        self.assertEqual(tr_int32.copy().trim(1, 2).data.dtype, np.int32)
        self.assertEqual(tr_int64.copy().trim(1, 2).data.dtype, np.int64)
        self.assertEqual(tr_float32.copy().trim(1, 2).data.dtype, np.float32)
        self.assertEqual(tr_float64.copy().trim(1, 2).data.dtype, np.float64)

        # Filtering. SciPy converts data to 64bit floats. Filters are
        # numerically tricky so a higher accuracy is justified here.
        self.assertEqual(
            tr_int32.copy().filter("lowpass", freq=2.0).data.dtype,
            np.float64)
        self.assertEqual(
            tr_int64.copy().filter("lowpass", freq=2.0).data.dtype,
            np.float64)
        self.assertEqual(
            tr_float32.copy().filter("lowpass", freq=2.0).data.dtype,
            np.float64)
        self.assertEqual(
            tr_float64.copy().filter("lowpass", freq=2.0).data.dtype,
            np.float64)

        # Decimation should not change the dtype.
        self.assertEqual(
            tr_int32.copy().decimate(factor=2, no_filter=True).data.dtype,
            np.int32)
        self.assertEqual(
            tr_int64.copy().decimate(factor=2, no_filter=True).data.dtype,
            np.int64)
        self.assertEqual(
            tr_float32.copy().decimate(factor=2, no_filter=True).data.dtype,
            np.float32)
        self.assertEqual(
            tr_float64.copy().decimate(factor=2, no_filter=True).data.dtype,
            np.float64)

        # Detrending will upcast integers but should not touch floats.
        self.assertEqual(tr_int32.copy().detrend("simple").data.dtype,
                         np.float64)
        self.assertEqual(tr_int64.copy().detrend("simple").data.dtype,
                         np.float64)
        self.assertEqual(tr_float32.copy().detrend("simple").data.dtype,
                         np.float32)
        self.assertEqual(tr_float64.copy().detrend("simple").data.dtype,
                         np.float64)
        self.assertEqual(tr_int32.copy().detrend("linear").data.dtype,
                         np.float64)
        self.assertEqual(tr_int64.copy().detrend("linear").data.dtype,
                         np.float64)
        self.assertEqual(tr_float32.copy().detrend("linear").data.dtype,
                         np.float32)
        self.assertEqual(tr_float64.copy().detrend("linear").data.dtype,
                         np.float64)
        self.assertEqual(tr_int32.copy().detrend("constant").data.dtype,
                         np.float64)
        self.assertEqual(tr_int64.copy().detrend("constant").data.dtype,
                         np.float64)
        self.assertEqual(tr_float32.copy().detrend("constant").data.dtype,
                         np.float32)
        self.assertEqual(tr_float64.copy().detrend("constant").data.dtype,
                         np.float64)
        self.assertEqual(
            tr_int32.copy().detrend("polynomial", order=3).data.dtype,
            np.float64)
        self.assertEqual(
            tr_int64.copy().detrend("polynomial", order=3).data.dtype,
            np.float64)
        self.assertEqual(
            tr_float32.copy().detrend("polynomial", order=3).data.dtype,
            np.float32)
        self.assertEqual(
            tr_float64.copy().detrend("polynomial", order=3).data.dtype,
            np.float64)
        self.assertEqual(
            tr_int32.copy().detrend("spline", order=3, dspline=100).data.dtype,
            np.float64)
        self.assertEqual(
            tr_int64.copy().detrend("spline", order=3, dspline=100).data.dtype,
            np.float64)
        self.assertEqual(
            tr_float32.copy().detrend("spline", order=3,
                                      dspline=100).data.dtype,
            np.float32)
        self.assertEqual(
            tr_float64.copy().detrend("spline", order=3,
                                      dspline=100).data.dtype,
            np.float64)

        # Tapering. Upcast to float64 but don't change float32.
        self.assertEqual(tr_int32.copy().taper(0.05, "hann").data.dtype,
                         np.float64)
        self.assertEqual(tr_int64.copy().taper(0.05, "hann").data.dtype,
                         np.float64)
        self.assertEqual(tr_float32.copy().taper(0.05, "hann").data.dtype,
                         np.float32)
        self.assertEqual(tr_float64.copy().taper(0.05, "hann").data.dtype,
                         np.float64)

        # Normalizing. Upcast to float64 but don't change float32.
        self.assertEqual(tr_int32.copy().normalize().data.dtype, np.float64)
        self.assertEqual(tr_int64.copy().normalize().data.dtype, np.float64)
        self.assertEqual(tr_float32.copy().normalize().data.dtype, np.float32)
        self.assertEqual(tr_float64.copy().normalize().data.dtype, np.float64)

        # Differentiate. Upcast to float64 but don't change float32.
        self.assertEqual(tr_int32.copy().differentiate().data.dtype,
                         np.float64)
        self.assertEqual(tr_int64.copy().differentiate().data.dtype,
                         np.float64)
        self.assertEqual(tr_float32.copy().differentiate().data.dtype,
                         np.float32)
        self.assertEqual(tr_float64.copy().differentiate().data.dtype,
                         np.float64)

        # Integrate. Upcast to float64 but don't change float32.
        self.assertEqual(
            tr_int32.copy().integrate(method="cumtrapz").data.dtype,
            np.float64)
        self.assertEqual(
            tr_int64.copy().integrate(method="cumtrapz").data.dtype,
            np.float64)
        self.assertEqual(
            tr_float32.copy().integrate(method="cumtrapz").data.dtype,
            np.float32)
        self.assertEqual(
            tr_float64.copy().integrate(method="cumtrapz").data.dtype,
            np.float64)
        # The spline antiderivate always returns float64.
        self.assertEqual(
            tr_int32.copy().integrate(method="spline").data.dtype,
            np.float64)
        self.assertEqual(
            tr_int64.copy().integrate(method="spline").data.dtype,
            np.float64)
        self.assertEqual(
            tr_float32.copy().integrate(method="spline").data.dtype,
            np.float64)
        self.assertEqual(
            tr_float64.copy().integrate(method="spline").data.dtype,
            np.float64)

        # Simulation is an operation in the spectral domain so double
        # precision is a lot more accurate so it's fine here.
        paz_remove = {'poles': [-0.037004 + 0.037016j, -0.037004 - 0.037016j,
                                -251.33 + 0j],
                      'zeros': [0j, 0j], 'gain': 60077000.0,
                      'sensitivity': 2516778400.0}
        self.assertEqual(
            tr_int32.copy().simulate(paz_remove=paz_remove).data.dtype,
            np.float64)
        self.assertEqual(
            tr_int64.copy().simulate(paz_remove=paz_remove).data.dtype,
            np.float64)
        self.assertEqual(
            tr_float32.copy().simulate(paz_remove=paz_remove).data.dtype,
            np.float64)
        self.assertEqual(
            tr_float64.copy().simulate(paz_remove=paz_remove).data.dtype,
            np.float64)

        # Same with the fourier domain resampling.
        self.assertEqual(tr_int32.copy().resample(2.0).data.dtype, np.float64)
        self.assertEqual(tr_int64.copy().resample(2.0).data.dtype, np.float64)
        self.assertEqual(tr_float32.copy().resample(2.0).data.dtype,
                         np.float64)
        self.assertEqual(tr_float64.copy().resample(2.0).data.dtype,
                         np.float64)

        # Same with remove_response()
        inv = read_inventory()
        self.assertEqual(
            tr_int32.copy().remove_response(inventory=inv).data.dtype,
            np.float64)
        self.assertEqual(
            tr_int64.copy().remove_response(inventory=inv).data.dtype,
            np.float64)
        self.assertEqual(
            tr_float32.copy().remove_response(inventory=inv).data.dtype,
            np.float64)
        self.assertEqual(
            tr_float64.copy().remove_response(inventory=inv).data.dtype,
            np.float64)

        # Remove sensitivity does not have to change the dtype for float32.
        self.assertEqual(
            tr_int32.copy().remove_sensitivity(inventory=inv).data.dtype,
            np.float64)
        self.assertEqual(
            tr_int64.copy().remove_sensitivity(inventory=inv).data.dtype,
            np.float64)
        self.assertEqual(
            tr_float32.copy().remove_sensitivity(inventory=inv).data.dtype,
            np.float32)
        self.assertEqual(
            tr_float64.copy().remove_sensitivity(inventory=inv).data.dtype,
            np.float64)

        # Various interpolation routines.
        # Weighted average slopes is a custom C routine that only works with
        # double precision.
        self.assertEqual(
            tr_int32.copy().interpolate(
                1.0, method="weighted_average_slopes").data.dtype, np.float64)
        self.assertEqual(
            tr_int64.copy().interpolate(
                1.0, method="weighted_average_slopes").data.dtype, np.float64)
        self.assertEqual(
            tr_float32.copy().interpolate(
                1.0, method="weighted_average_slopes").data.dtype, np.float64)
        self.assertEqual(
            tr_float64.copy().interpolate(
                1.0, method="weighted_average_slopes").data.dtype, np.float64)
        # Scipy treats splines as double precision. No need to convert them.
        self.assertEqual(
            tr_int32.copy().interpolate(
                1.0, method="slinear").data.dtype, np.float64)
        self.assertEqual(
            tr_int64.copy().interpolate(
                1.0, method="slinear").data.dtype, np.float64)
        self.assertEqual(
            tr_float32.copy().interpolate(
                1.0, method="slinear").data.dtype, np.float64)
        self.assertEqual(
            tr_float64.copy().interpolate(
                1.0, method="slinear").data.dtype, np.float64)
        # Lanczos is a custom C routine that only works with double precision.
        self.assertEqual(
            tr_int32.copy().interpolate(
                1.0, method="lanczos", a=2).data.dtype, np.float64)
        self.assertEqual(
            tr_int64.copy().interpolate(
                1.0, method="lanczos", a=2).data.dtype, np.float64)
        self.assertEqual(
            tr_float32.copy().interpolate(
                1.0, method="lanczos", a=2).data.dtype, np.float64)
        self.assertEqual(
            tr_float64.copy().interpolate(
                1.0, method="lanczos", a=2).data.dtype, np.float64)

    def test_set_trace_id(self):
        """
        Test setter of `id` property.
        """
        tr = Trace()
        tr.stats.location = "00"
        # check setting net/sta/loc/cha with an ID
        tr.id = "GR.FUR..HHZ"
        self.assertEqual(tr.stats.network, "GR")
        self.assertEqual(tr.stats.station, "FUR")
        self.assertEqual(tr.stats.location, "")
        self.assertEqual(tr.stats.channel, "HHZ")
        # check that invalid types will raise
        invalid = (True, False, -10, 0, 1.0, [1, 4, 3, 2], np.ones(4))
        for id_ in invalid:
            with self.assertRaises(TypeError):
                tr.id = id_
        # check that invalid ID strings will raise
        invalid = ("ABCD", "AB.CD", "AB.CD.00", "..EE", "....",
                   "GR.FUR..HHZ.", "GR.FUR..HHZ...")
        for id_ in invalid:
            with self.assertRaises(ValueError):
                tr.id = id_


def suite():
    return unittest.makeSuite(TraceTestCase, 'test')


if __name__ == '__main__':
    unittest.main(defaultTest='suite')