-
Notifications
You must be signed in to change notification settings - Fork 21
New issue
Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.
By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.
Already on GitHub? Sign in to your account
Add Astropy view support to afw.table (DM-5641) #64
Changes from all commits
File filter
Filter by extension
Conversations
Jump to
Diff view
Diff view
There are no files selected for viewing
Original file line number | Diff line number | Diff line change |
---|---|---|
|
@@ -202,3 +202,70 @@ def processArray(a): | |
else: | ||
d[name] = processArray(self.get(schemaItem.key)) | ||
return d | ||
|
||
def BaseCatalog_asAstropy(self, cls=None, copy=False, unviewable="copy"): | ||
There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. I don't really like There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. I'm fairly ambivalent about underscores vs. CamelCase here; overall I have a slight preference for switching everything to underscores, but I don't want to switch just some interfaces because then it becomes hard to remember which convention to use where. But I also don't want people to be stuck trying to remember whether it's In any case, I'd like to avoid appending "table"; I think that's pretty strongly implied by the fact that this is a Catalog object, and I do think this is something people may end up typing a fair amount in interactive use, so fewer characters matters. There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. It's "import astropy" so I don't think that people will think "asAstroPy". I vote for asAstropy for consistency with the rest of our camelCaseCode. There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. I think my worry about confusion comes from the fact that I write But the NumPy and Astropy documentation and web pages seem to be quite internally consistent on the capitalization of the "p" while being unfortunately inconsistent with each other, so I maintain it's not my fault. |
||
"""! | ||
Return an astropy.table.Table (or subclass thereof) view into this catalog. | ||
|
||
@param[in] cls Table subclass to use; None implies astropy.table.Table itself. | ||
Use astropy.table.QTable to get Quantity columns. | ||
|
||
@param[in] copy Whether to copy data from the LSST catalog to the astropy table. | ||
Not copying is usually faster, but can keep memory from being | ||
freed if columns are later removed from the Astropy view. | ||
|
||
@param[in] unviewable One of the following options, indicating how to handle field types | ||
There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. Does this method exist because you can't get the There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. Yes and no. This argument is indeed the only one we can't get through the There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. Ok. So we have both. There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. If There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. It's not actually a leak; it's just that you're keeping a large array alive via a view into a subset of it. It's exactly the same as what happens here:
There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. Since this is the first case of using There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. On the philosophical side, when I see Right now There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. If there was no precedent here, I think I'd feel pretty strongly that All that said, using constructors for type casting is very much an established pattern in Python, even way down in the standard library. I think that may have started largely because it's familiar to people coming from C++, Java, or other strongly-typed languages with overloading (where this pattern very much makes sense), but it's here now, and it's not something I can wish away. I don't have a well-formed opinion about Anyhow, I think the current interface should accept |
||
(string and Flag) for which views cannot be constructed: | ||
- 'copy' (default): copy only the unviewable fields. | ||
- 'raise': raise ValueError if unviewable fields are present. | ||
- 'skip': do not include unviewable fields in the Astropy Table. | ||
This option is ignored if copy=True. | ||
""" | ||
import astropy.table | ||
if cls is None: | ||
cls = astropy.table.Table | ||
if unviewable not in ("copy", "raise", "skip"): | ||
raise ValueError("'unviewable' must be one of 'copy', 'raise', or 'skip'") | ||
ps = self.getMetadata() | ||
meta = ps.toOrderedDict() if ps is not None else None | ||
columns = [] | ||
items = self.schema.extract("*", ordered=True) | ||
for name, item in items.iteritems(): | ||
key = item.key | ||
unit = item.field.getUnits() or None # use None instead of "" when empty | ||
if key.getTypeString() == "String": | ||
if not copy: | ||
if unviewable == "raise": | ||
raise ValueError("Cannot extract string unless copy=True or unviewable='copy' or 'skip'.") | ||
elif unviewable == "skip": | ||
continue | ||
data = numpy.zeros(len(self), dtype=numpy.dtype((str, key.getSize()))) | ||
for i, record in enumerate(self): | ||
data[i] = record.get(key) | ||
elif key.getTypeString() == "Flag": | ||
if not copy: | ||
if unviewable == "raise": | ||
raise ValueError( | ||
"Cannot extract packed bit columns unless copy=True or unviewable='copy' or 'skip'." | ||
) | ||
elif unviewable == "skip": | ||
continue | ||
data = self.columns.get_bool_array(key) | ||
elif key.getTypeString() == "Angle": | ||
data = self.columns.get(key) | ||
unit = "radian" | ||
if copy: | ||
data = data.copy() | ||
else: | ||
data = self.columns.get(key) | ||
if copy: | ||
data = data.copy() | ||
columns.append( | ||
astropy.table.Column( | ||
data, | ||
name=item.field.getName(), | ||
unit=unit, | ||
description=item.field.getDoc() | ||
) | ||
) | ||
return cls(columns, meta=meta, copy=False) |
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,197 @@ | ||
#!/usr/bin/env python2 | ||
from __future__ import absolute_import, division | ||
|
||
# | ||
# LSST Data Management System | ||
# Copyright 2016 AURA/LSST | ||
# | ||
# This product includes software developed by the | ||
# LSST Project (http://www.lsst.org/). | ||
# | ||
# This program is free software: you can redistribute it and/or modify | ||
# it under the terms of the GNU General Public License as published by | ||
# the Free Software Foundation, either version 3 of the License, or | ||
# (at your option) any later version. | ||
# | ||
# This program is distributed in the hope that it will be useful, | ||
# but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
# GNU General Public License for more details. | ||
# | ||
# You should have received a copy of the LSST License Statement and | ||
# the GNU General Public License along with this program. If not, | ||
# see <http://www.lsstcorp.org/LegalNotices/>. | ||
# | ||
|
||
""" | ||
Tests for Astropy views into afw.table Catalogs | ||
There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. Am I correct in thinking that these tests are not testing the new functionality in Astropy but are testing that the There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. Basically correct. The tests do not exercise any new Astropy functionality. We do have a method that will hopefully work with v1.2, but that's untested. But even once v1.2 is out, I'd like to keep the There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. As I say above, I would prefer it if we just said "you pass this afw table to the astropy table constructor" rather than "you call this special exporter routine because it has an extra feature". Getting some extra There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. Oh, and my main comment here was that I'd like a comment in this test explaining that it's not actually testing the Astropy native constructor. There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. Comment added. |
||
|
||
Run with: | ||
./testAstropyTableViews.py | ||
or | ||
python | ||
>>> import testAstropyTableViews; testAstropyTableViews.run() | ||
""" | ||
|
||
import unittest | ||
import operator | ||
|
||
import numpy | ||
import astropy.table | ||
import astropy.units | ||
|
||
import lsst.utils.tests | ||
import lsst.afw.table | ||
|
||
|
||
class AstropyTableViewTestCase(lsst.utils.tests.TestCase): | ||
"""Test that we can construct Astropy views to afw.table Catalog objects. | ||
|
||
This test case does not yet test the syntax | ||
|
||
table = astropy.table.Table(lsst_catalog) | ||
|
||
which is made available by BaseCatalog.__astropy_table__, as this will not | ||
be available until Astropy 1.2 is released. However, this simply | ||
delegates to BaseCatalog.asAstropy, which can also be called directly. | ||
""" | ||
|
||
def setUp(self): | ||
schema = lsst.afw.table.Schema() | ||
self.k1 = schema.addField("a1", type=float, units="meter", doc="a1 (meter)") | ||
self.k2 = schema.addField("a2", type=int, doc="a2 (unitless)") | ||
self.k3 = schema.addField("a3", type="ArrayF", size=3, units="count", doc="a3 (array, counts)") | ||
self.k4 = schema.addField("a4", type="Flag", doc="a4 (flag)") | ||
self.k5 = lsst.afw.table.CoordKey.addFields(schema, "a5", "a5 coordinate") | ||
self.k6 = schema.addField("a6", type=str, size=8, doc="a6 (str)") | ||
self.catalog = lsst.afw.table.BaseCatalog(schema) | ||
self.data = [ | ||
{ | ||
"a1": 5.0, "a2": 3, "a3": numpy.array([0.5, 0.0, -0.5], dtype=numpy.float32), | ||
"a4": True, "a5_ra": 45.0*lsst.afw.geom.degrees, "a5_dec": 30.0*lsst.afw.geom.degrees, | ||
"a6": "bubbles" | ||
}, | ||
{ | ||
"a1": 2.5, "a2": 7, "a3": numpy.array([1.0, 0.5, -1.5], dtype=numpy.float32), | ||
"a4": False, "a5_ra": 25.0*lsst.afw.geom.degrees, "a5_dec": -60.0*lsst.afw.geom.degrees, | ||
"a6": "pingpong" | ||
}, | ||
] | ||
for d in self.data: | ||
record = self.catalog.addNew() | ||
for k, v in d.iteritems(): | ||
record.set(k, v) | ||
|
||
def tearDown(self): | ||
del self.k1 | ||
del self.k2 | ||
del self.k3 | ||
del self.k4 | ||
del self.k5 | ||
del self.k6 | ||
del self.catalog | ||
del self.data | ||
|
||
def testQuantityColumn(self): | ||
"""Test that a column with units is handled as expected by Table and QTable. | ||
""" | ||
v1 = self.catalog.asAstropy(cls=astropy.table.Table, unviewable="skip") | ||
self.assertEqual(v1["a1"].unit, astropy.units.Unit("m")) | ||
self.assertClose(v1["a1"], self.catalog["a1"]) | ||
self.assertNotIsInstance(v1["a1"], astropy.units.Quantity) | ||
v2 = self.catalog.asAstropy(cls=astropy.table.QTable, unviewable="skip") | ||
self.assertEqual(v2["a1"].unit, astropy.units.Unit("m")) | ||
self.assertClose(v2["a1"]/astropy.units.Quantity(self.catalog["a1"]*100, "cm"), 1.0) | ||
self.assertIsInstance(v2["a1"], astropy.units.Quantity) | ||
|
||
def testUnitlessColumn(self): | ||
"""Test that a column without units is handled as expected by Table and QTable. | ||
""" | ||
v1 = self.catalog.asAstropy(cls=astropy.table.Table, unviewable="skip") | ||
self.assertEqual(v1["a2"].unit, None) | ||
self.assertClose(v1["a2"], self.catalog["a2"]) # use assertClose just because it handles arrays | ||
v2 = self.catalog.asAstropy(cls=astropy.table.QTable, unviewable="skip") | ||
self.assertEqual(v2["a2"].unit, None) | ||
self.assertClose(v2["a2"], self.catalog["a2"]) | ||
|
||
def testArrayColumn(self): | ||
"""Test that an array column appears as a 2-d array with the expected shape. | ||
""" | ||
v = self.catalog.asAstropy(unviewable="skip") | ||
self.assertClose(v["a3"], self.catalog["a3"]) | ||
|
||
def testFlagColumn(self): | ||
"""Test that Flag columns can be viewed if copy=True or unviewable="copy". | ||
""" | ||
v1 = self.catalog.asAstropy(unviewable="copy") | ||
self.assertClose(v1["a4"], self.catalog["a4"]) | ||
v2 = self.catalog.asAstropy(copy=True) | ||
self.assertClose(v2["a4"], self.catalog["a4"]) | ||
|
||
def testCoordColumn(self): | ||
"""Test that Coord columns appears as a pair of columns with correct angle units. | ||
""" | ||
v1 = self.catalog.asAstropy(cls=astropy.table.Table, unviewable="skip") | ||
self.assertClose(v1["a5_ra"], self.catalog["a5_ra"]) | ||
self.assertEqual(v1["a5_ra"].unit, astropy.units.Unit("rad")) | ||
self.assertNotIsInstance(v1["a5_ra"], astropy.units.Quantity) | ||
self.assertClose(v1["a5_dec"], self.catalog["a5_dec"]) | ||
self.assertEqual(v1["a5_dec"].unit, astropy.units.Unit("rad")) | ||
self.assertNotIsInstance(v1["a5_dec"], astropy.units.Quantity) | ||
v2 = self.catalog.asAstropy(cls=astropy.table.QTable, unviewable="skip") | ||
self.assertClose(v2["a5_ra"]/astropy.units.Quantity(self.catalog["a5_ra"], unit="rad"), 1.0) | ||
self.assertEqual(v2["a5_ra"].unit, astropy.units.Unit("rad")) | ||
self.assertIsInstance(v2["a5_ra"], astropy.units.Quantity) | ||
self.assertClose(v2["a5_dec"]/astropy.units.Quantity(self.catalog["a5_dec"], unit="rad"), 1.0) | ||
self.assertEqual(v2["a5_dec"].unit, astropy.units.Unit("rad")) | ||
self.assertIsInstance(v2["a5_dec"], astropy.units.Quantity) | ||
|
||
def testStringColumn(self): | ||
"""Test that string columns can be viewed if copy=True or unviewable='copy'. | ||
""" | ||
v1 = self.catalog.asAstropy(unviewable="copy") | ||
self.assertEqual(v1["a6"][0], self.data[0]["a6"]) | ||
self.assertEqual(v1["a6"][1], self.data[1]["a6"]) | ||
v2 = self.catalog.asAstropy(copy=True) | ||
self.assertEqual(v2["a6"][0], self.data[0]["a6"]) | ||
self.assertEqual(v2["a6"][1], self.data[1]["a6"]) | ||
|
||
def testRaiseOnUnviewable(self): | ||
"""Test that we can't view this table without copying, since it has Flag and String columns. | ||
""" | ||
self.assertRaises(ValueError, self.catalog.asAstropy, copy=False, unviewable="raise") | ||
|
||
def testNoUnnecessaryCopies(self): | ||
"""Test that fields that aren't Flag or String are not copied when copy=False (the default). | ||
""" | ||
v1 = self.catalog.asAstropy(unviewable="copy") | ||
v1["a2"][0] = 4 | ||
self.assertEqual(self.catalog[0]["a2"], 4) | ||
v2 = self.catalog.asAstropy(unviewable="skip") | ||
v2["a2"][1] = 10 | ||
self.assertEqual(self.catalog[1]["a2"], 10) | ||
|
||
def testUnviewableSkip(self): | ||
"""Test that we can skip unviewable columns. | ||
""" | ||
v1 = self.catalog.asAstropy(unviewable="skip") | ||
self.assertRaises(KeyError, operator.getitem, v1, "a4") | ||
self.assertRaises(KeyError, operator.getitem, v1, "a6") | ||
|
||
|
||
def suite(): | ||
"""Returns a suite containing all the test cases in this module.""" | ||
|
||
lsst.utils.tests.init() | ||
|
||
suites = [] | ||
suites += unittest.makeSuite(AstropyTableViewTestCase) | ||
suites += unittest.makeSuite(lsst.utils.tests.MemoryTestCase) | ||
return unittest.TestSuite(suites) | ||
|
||
def run(shouldExit = False): | ||
"""Run the tests""" | ||
lsst.utils.tests.run(suite(), shouldExit) | ||
|
||
if __name__ == "__main__": | ||
run(True) |
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
Shouldn't the kwargs have been forwarded on here?
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
Thought I did that, but apparently not. I'll create a mini-ticket to fix.