numpy · juliantaylor · Sep 2, 2014 · Aug 31, 2014 · Sep 1, 2014
diff --git a/numpy/core/numeric.py b/numpy/core/numeric.py
@@ -2153,6 +2153,41 @@ def identity(n, dtype=None):
     from numpy import eye
     return eye(n, dtype=dtype)
 
+def _allclose_points(a, b, rtol=1.e-5, atol=1.e-8):
+    """
+    This is the point-wise inner calculation of 'allclose', which is subtly
+    different from 'isclose'.  Provided as a comparison routine for use in
+    testing.assert_allclose.
+    See those routines for further details.
+
+    """
+    x = array(a, copy=False, ndmin=1)
+    y = array(b, copy=False, ndmin=1)
+
+    # make sure y is an inexact type to avoid abs(MIN_INT); will cause
+    # casting of x later.
+    dtype = multiarray.result_type(y, 1.)
+    y = array(y, dtype=dtype, copy=False)
+
+    xinf = isinf(x)
+    yinf = isinf(y)
+    if any(xinf) or any(yinf):
+        # Check that x and y have inf's only in the same positions
+        if not all(xinf == yinf):
+            return False
+        # Check that sign of inf's in x and y is the same
+        if not all(x[xinf] == y[xinf]):
+            return False
+
+        x = x[~xinf]
+        y = y[~xinf]
+
+    # ignore invalid fpe's
+    with errstate(invalid='ignore'):
+        r = less_equal(abs(x - y), atol + rtol * abs(y))
+
+    return r
+
 def allclose(a, b, rtol=1.e-5, atol=1.e-8):
     """
     Returns True if two arrays are element-wise equal within a tolerance.
@@ -2208,32 +2243,7 @@ def allclose(a, b, rtol=1.e-5, atol=1.e-8):
     False
 
     """
-    x = array(a, copy=False, ndmin=1)
-    y = array(b, copy=False, ndmin=1)
-
-    # make sure y is an inexact type to avoid abs(MIN_INT); will cause
-    # casting of x later.
-    dtype = multiarray.result_type(y, 1.)
-    y = array(y, dtype=dtype, copy=False)
-
-    xinf = isinf(x)
-    yinf = isinf(y)
-    if any(xinf) or any(yinf):
-        # Check that x and y have inf's only in the same positions
-        if not all(xinf == yinf):
-            return False
-        # Check that sign of inf's in x and y is the same
-        if not all(x[xinf] == y[xinf]):
-            return False
-
-        x = x[~xinf]
-        y = y[~xinf]
-
-    # ignore invalid fpe's
-    with errstate(invalid='ignore'):
-        r = all(less_equal(abs(x - y), atol + rtol * abs(y)))
-
-    return r
+    return all(_allclose_points(a, b, rtol=rtol, atol=atol))
 
 def isclose(a, b, rtol=1.e-5, atol=1.e-8, equal_nan=False):
     """

diff --git a/numpy/testing/tests/test_utils.py b/numpy/testing/tests/test_utils.py
@@ -449,6 +449,15 @@ def test_min_int(self):
         # Should not raise:
         assert_allclose(a, a)
 
+    def test_report_fail_percentage(self):
+        a = np.array([1, 1, 1, 1])
+        b = np.array([1, 1, 1, 2])
+        try:
+            assert_allclose(a, b)
+            msg = ''
+        except AssertionError as exc:
+            msg = exc.args[0]
+        self.assertTrue("mismatch 25.0%" in msg)
 
 class TestArrayAlmostEqualNulp(unittest.TestCase):
     @dec.knownfailureif(True, "Github issue #347")

diff --git a/numpy/testing/utils.py b/numpy/testing/utils.py
@@ -1289,7 +1289,7 @@ def assert_allclose(actual, desired, rtol=1e-7, atol=0,
     """
     import numpy as np
     def compare(x, y):
-        return np.allclose(x, y, rtol=rtol, atol=atol)
+        return np.core.numeric._allclose_points(x, y, rtol=rtol, atol=atol)
 
     actual, desired = np.asanyarray(actual), np.asanyarray(desired)
     header = 'Not equal to tolerance rtol=%g, atol=%g' % (rtol, atol)