Merge branch 'pull-141'

* pull-141: (167 commits)
  ENH: missingdata: Make PyArray_Converter and PyArray_OutputConverter safer for legacy code
  DOC: missingdata: Add a mention of the design NEP, and masks vs bitpatterns
  DOC: missingdata: Updates from pull request feedback
  DOC: missingdata: Updates based on pull request feedback
  ENH: nditer: Change the Python nditer exposure to automatically add NPY_ITER_USE_MASKNA
  ENH: missingdata: Make comparisons with NA return NA(dtype='bool')
  BLD: core: onefile build fix and Python3 compatibility change
  DOC: Mention the update to np.all and np.any in the release notes
  TST: dtype: Adjust void dtype test to pass without raising a zero-size exception
  STY: Remove trailing whitespace
  TST: missingdata: Write some tests for the np.any and np.all NA behavior
  ENH: missingdata: Make numpy.all follow the NA && False == False rule
  ENH: missingdata: Make numpy.all follow the NA || True == True rule
  DOC: missingdata: Also show what assigning a non-NA value does in each case
  DOC: missingdata: Add introductory documentation for NA-masked arrays
  ENH: core: Rename PyArrayObject_fieldaccess to PyArrayObject_fields
  DOC: missingdata: Some tweaks to the NA mask documentation
  DOC: missingdata: Add example of a C-API function supporting NA masks
  DOC: missingdata: Documenting C API for NA-masked arrays
  ENH: missingdata: Finish adding C-API access to the NpyNA object
  ...

1 files changed, 18 insertions, 9 deletions

diff --git a/numpy/matrixlib/defmatrix.py b/numpy/matrixlib/defmatrix.py
index aac123e59..dbf2909fd 100644
--- a/numpy/matrixlib/defmatrix.py
+++ b/numpy/matrixlib/defmatrix.py
@@ -375,6 +375,15 @@ class matrix(N.ndarray):
         else:
             raise ValueError("unsupported axis")
 
+    def _collapse(self, axis):
+        """A convenience function for operations that want to collapse
+        to a scalar like _align, but are using keepdims=True
+        """
+        if axis is None:
+            return self[0,0]
+        else:
+            return self
+
     # Necessary because base-class tolist expects dimension
     #  reduction by x[0]
     def tolist(self):
@@ -432,7 +441,7 @@ class matrix(N.ndarray):
                 [ 7.]])
 
         """
-        return N.ndarray.sum(self, axis, dtype, out)._align(axis)
+        return N.ndarray.sum(self, axis, dtype, out, keepdims=True)._collapse(axis)
 
     def mean(self, axis=None, dtype=None, out=None):
         """
@@ -466,7 +475,7 @@ class matrix(N.ndarray):
                 [ 9.5]])
 
         """
-        return N.ndarray.mean(self, axis, dtype, out)._align(axis)
+        return N.ndarray.mean(self, axis, dtype, out, keepdims=True)._collapse(axis)
 
     def std(self, axis=None, dtype=None, out=None, ddof=0):
         """
@@ -500,7 +509,7 @@ class matrix(N.ndarray):
                 [ 1.11803399]])
 
         """
-        return N.ndarray.std(self, axis, dtype, out, ddof)._align(axis)
+        return N.ndarray.std(self, axis, dtype, out, ddof, keepdims=True)._collapse(axis)
 
     def var(self, axis=None, dtype=None, out=None, ddof=0):
         """
@@ -534,7 +543,7 @@ class matrix(N.ndarray):
                 [ 1.25]])
 
         """
-        return N.ndarray.var(self, axis, dtype, out, ddof)._align(axis)
+        return N.ndarray.var(self, axis, dtype, out, ddof, keepdims=True)._collapse(axis)
 
     def prod(self, axis=None, dtype=None, out=None):
         """
@@ -567,7 +576,7 @@ class matrix(N.ndarray):
                 [7920]])
 
         """
-        return N.ndarray.prod(self, axis, dtype, out)._align(axis)
+        return N.ndarray.prod(self, axis, dtype, out, keepdims=True)._collapse(axis)
 
     def any(self, axis=None, out=None):
         """
@@ -590,7 +599,7 @@ class matrix(N.ndarray):
                 returns `ndarray`
 
         """
-        return N.ndarray.any(self, axis, out)._align(axis)
+        return N.ndarray.any(self, axis, out, keepdims=True)._collapse(axis)
 
     def all(self, axis=None, out=None):
         """
@@ -630,7 +639,7 @@ class matrix(N.ndarray):
                 [False]], dtype=bool)
 
         """
-        return N.ndarray.all(self, axis, out)._align(axis)
+        return N.ndarray.all(self, axis, out, keepdims=True)._collapse(axis)
 
     def max(self, axis=None, out=None):
         """
@@ -665,7 +674,7 @@ class matrix(N.ndarray):
                 [11]])
 
         """
-        return N.ndarray.max(self, axis, out)._align(axis)
+        return N.ndarray.max(self, axis, out, keepdims=True)._collapse(axis)
 
     def argmax(self, axis=None, out=None):
         """
@@ -735,7 +744,7 @@ class matrix(N.ndarray):
                 [-11]])
 
         """
-        return N.ndarray.min(self, axis, out)._align(axis)
+        return N.ndarray.min(self, axis, out, keepdims=True)._collapse(axis)
 
     def argmin(self, axis=None, out=None):
         """