BUG: Force allclose logic to use inexact type

Casting y to an inexact type fixes problems such as
abs(MIN_INT) < 0, and generally makes sense since the allclose
logic is inherently for float types.

1 files changed, 9 insertions, 5 deletions

diff --git a/numpy/testing/utils.py b/numpy/testing/utils.py
index 82aa1e39c..97908c7e8 100644
--- a/numpy/testing/utils.py
+++ b/numpy/testing/utils.py
@@ -793,7 +793,7 @@ def assert_array_almost_equal(x, y, decimal=6, err_msg='', verbose=True):
      y: array([ 1.     ,  2.33333,  5.     ])
 
     """
-    from numpy.core import around, number, float_
+    from numpy.core import around, number, float_, result_type, array
     from numpy.core.numerictypes import issubdtype
     from numpy.core.fromnumeric import any as npany
     def compare(x, y):
@@ -811,17 +811,21 @@ def assert_array_almost_equal(x, y, decimal=6, err_msg='', verbose=True):
         except (TypeError, NotImplementedError):
             pass
 
-        if x.dtype.kind == 'b' and y.dtype.kind == 'b':
-            z = x ^ y
-        else:
-            z = abs(x-y)
+        # make sure y is an inexact type to avoid abs(MIN_INT); will cause
+        # casting of x later.
+        dtype = result_type(y, 1.)
+        y = array(y, dtype=dtype, copy=False)
+        z = abs(x-y)
 
         if not issubdtype(z.dtype, number):
             z = z.astype(float_) # handle object arrays
+
         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))
 
+
 def assert_array_less(x, y, err_msg='', verbose=True):
     """
     Raise an assertion if two array_like objects are not ordered by less than.