Merge pull request #4541 from ElDeveloper/issue-2367

BUG:change formatting of assert_array_almost_equal

numpy/testing/tests/test_utils.py

@@ -134,6 +134,49 @@ def test_recarrays(self):
 
         self._test_not_equal(c, b)
 
+class TestBuildErrorMessage(unittest.TestCase):
+    def test_build_err_msg_defaults(self):
+        x = np.array([1.00001, 2.00002, 3.00003])
+        y = np.array([1.00002, 2.00003, 3.00004])
+        err_msg = 'There is a mismatch'
+
+        a = build_err_msg([x, y], err_msg)
+        b = ('\nItems are not equal: There is a mismatch\n ACTUAL: array([ '
+             '1.00001,  2.00002,  3.00003])\n DESIRED: array([ 1.00002,  '
+             '2.00003,  3.00004])')
+        self.assertEqual(a, b)
+
+    def test_build_err_msg_no_verbose(self):
+        x = np.array([1.00001, 2.00002, 3.00003])
+        y = np.array([1.00002, 2.00003, 3.00004])
+        err_msg = 'There is a mismatch'
+
+        a = build_err_msg([x, y], err_msg, verbose=False)
+        b = '\nItems are not equal: There is a mismatch'
+        self.assertEqual(a, b)
+
+    def test_build_err_msg_custom_names(self):
+        x = np.array([1.00001, 2.00002, 3.00003])
+        y = np.array([1.00002, 2.00003, 3.00004])
+        err_msg = 'There is a mismatch'
+
+        a = build_err_msg([x, y], err_msg, names=('FOO', 'BAR'))
+        b = ('\nItems are not equal: There is a mismatch\n FOO: array([ '
+             '1.00001,  2.00002,  3.00003])\n BAR: array([ 1.00002,  2.00003,  '
+             '3.00004])')
+        self.assertEqual(a, b)
+
+    def test_build_err_msg_custom_precision(self):
+        x = np.array([1.000000001, 2.00002, 3.00003])
+        y = np.array([1.000000002, 2.00003, 3.00004])
+        err_msg = 'There is a mismatch'
+
+        a = build_err_msg([x, y], err_msg, precision=10)
+        b = ('\nItems are not equal: There is a mismatch\n ACTUAL: array([ '
+             '1.000000001,  2.00002    ,  3.00003    ])\n DESIRED: array([ '
+             '1.000000002,  2.00003    ,  3.00004    ])')
+        self.assertEqual(a, b)
+
 class TestEqual(TestArrayEqual):
     def setUp(self):
         self._assert_func = assert_equal
@@ -239,6 +282,31 @@ def test_complex(self):
         self._test_not_equal(x, y)
         self._test_not_equal(x, z)
 
+    def test_error_message(self):
+        """Check the message is formatted correctly for the decimal value"""
+        x = np.array([1.00000000001, 2.00000000002, 3.00003])
+        y = np.array([1.00000000002, 2.00000000003, 3.00004])
+
+        # test with a different amount of decimal digits
+        # note that we only check for the formatting of the arrays themselves
+        b = ('x: array([ 1.00000000001,  2.00000000002,  3.00003     '
+             ' ])\n y: array([ 1.00000000002,  2.00000000003,  3.00004      ])')
+        try:
+            self._assert_func(x, y, decimal=12)
+        except AssertionError as e:
+            # remove anything that's not the array string
+            self.assertEqual(str(e).split('%)\n ')[1], b)
+
+        # with the default value of decimal digits, only the 3rd element differs
+        # note that we only check for the formatting of the arrays themselves
+        b = ('x: array([ 1.     ,  2.     ,  3.00003])\n y: array([ 1.     ,  '
+             '2.     ,  3.00004])')
+        try:
+            self._assert_func(x, y)
+        except AssertionError as e:
+            # remove anything that's not the array string
+            self.assertEqual(str(e).split('%)\n ')[1], b)
+
 class TestApproxEqual(unittest.TestCase):
     def setUp(self):
         self._assert_func = assert_approx_equal

numpy/testing/utils.py

@@ -9,8 +9,9 @@
 import re
 import operator
 import warnings
+from functools import partial
 from .nosetester import import_nose
-from numpy.core import float32, empty, arange
+from numpy.core import float32, empty, arange, array_repr, ndarray
 
 if sys.version_info[0] >= 3:
     from io import StringIO
@@ -190,8 +191,7 @@ def memusage(processName="python", instance=0):
                                         win32pdh.PDH_FMT_LONG, None)
 
 def build_err_msg(arrays, err_msg, header='Items are not equal:',
-                  verbose=True,
-                  names=('ACTUAL', 'DESIRED')):
+                  verbose=True, names=('ACTUAL', 'DESIRED'), precision=8):
     msg = ['\n' + header]
     if err_msg:
         if err_msg.find('\n') == -1 and len(err_msg) < 79-len(header):
@@ -200,8 +200,15 @@ def build_err_msg(arrays, err_msg, header='Items are not equal:',
             msg.append(err_msg)
     if verbose:
         for i, a in enumerate(arrays):
+
+            if isinstance(a, ndarray):
+                # precision argument is only needed if the objects are ndarrays
+                r_func = partial(array_repr, precision=precision)
+            else:
+                r_func = repr
+
             try:
-                r = repr(a)
+                r = r_func(a)
             except:
                 r = '[repr failed]'
             if r.count('\n') > 3:
@@ -575,7 +582,7 @@ def assert_approx_equal(actual,desired,significant=7,err_msg='',verbose=True):
         raise AssertionError(msg)
 
 def assert_array_compare(comparison, x, y, err_msg='', verbose=True,
-                         header=''):
+                         header='', precision=6):
     from numpy.core import array, isnan, isinf, any, all, inf
     x = array(x, copy=False, subok=True)
     y = array(y, copy=False, subok=True)
@@ -592,7 +599,7 @@ def chk_same_position(x_id, y_id, hasval='nan'):
             msg = build_err_msg([x, y],
                                 err_msg + '\nx and y %s location mismatch:' \
                                 % (hasval), verbose=verbose, header=header,
-                                names=('x', 'y'))
+                                names=('x', 'y'), precision=precision)
             raise AssertionError(msg)
 
     try:
@@ -603,7 +610,7 @@ def chk_same_position(x_id, y_id, hasval='nan'):
                                 + '\n(shapes %s, %s mismatch)' % (x.shape,
                                                                   y.shape),
                                 verbose=verbose, header=header,
-                                names=('x', 'y'))
+                                names=('x', 'y'), precision=precision)
             if not cond :
                 raise AssertionError(msg)
 
@@ -648,7 +655,7 @@ def chk_same_position(x_id, y_id, hasval='nan'):
                                 err_msg
                                 + '\n(mismatch %s%%)' % (match,),
                                 verbose=verbose, header=header,
-                                names=('x', 'y'))
+                                names=('x', 'y'), precision=precision)
             if not cond :
                 raise AssertionError(msg)
     except ValueError as e:
@@ -657,7 +664,7 @@ def chk_same_position(x_id, y_id, hasval='nan'):
         header = 'error during assertion:\n\n%s\n\n%s' % (efmt, header)
 
         msg = build_err_msg([x, y], err_msg, verbose=verbose, header=header,
-                            names=('x', 'y'))
+                            names=('x', 'y'), precision=precision)
         raise ValueError(msg)
 
 def assert_array_equal(x, y, err_msg='', verbose=True):
@@ -825,7 +832,8 @@ def compare(x, y):
         return around(z, decimal) <= 10.0**(-decimal)
 
     assert_array_compare(compare, x, y, err_msg=err_msg, verbose=verbose,
-             header=('Arrays are not almost equal to %d decimals' % decimal))
+             header=('Arrays are not almost equal to %d decimals' % decimal),
+             precision=decimal)
 
 
 def assert_array_less(x, y, err_msg='', verbose=True):