MAINT: Tweak documentation of broadcast.nd and broadcast.ndim.

Note that the newly added `ndim` property is an alias for `nd` and
not available in numpy versions earlier than 1.12.

Add back the tests for `nd`. They can be removed if/when `nd` is
dropped.

Author: charris

numpy/add_newdocs.py

@@ -554,7 +554,7 @@ def luf(lamdaexpr, *args, **kwargs):
 
 add_newdoc('numpy.core', 'broadcast', ('ndim',
     """
-    Number of dimensions of broadcasted result.
+    Number of dimensions of broadcasted result. Alias for `nd`.
 
     .. versionadded:: 1.12.0
 
@@ -570,7 +570,8 @@ def luf(lamdaexpr, *args, **kwargs):
 
 add_newdoc('numpy.core', 'broadcast', ('nd',
     """
-    Number of dimensions of broadcasted result. Alias for `ndim`.
+    Number of dimensions of broadcasted result. For code intended for Numpy
+    1.12.0 and later the more consistent `ndim` is preferred.
 
     Examples
     --------

numpy/core/tests/test_numeric.py

@@ -2496,6 +2496,7 @@ def test_broadcast_in_args(self):
         for mit in mits:
             assert_equal(mit.shape, (5, 6, 7))
             assert_equal(mit.ndim, 3)
+            assert_equal(mit.nd, 3)
             assert_equal(mit.numiter, 4)
             for a, ia in zip(arrs, mit.iters):
                 assert_(a is ia.base)
@@ -2506,6 +2507,7 @@ def test_broadcast_single_arg(self):
         mit = np.broadcast(*arrs)
         assert_equal(mit.shape, (5, 6, 7))
         assert_equal(mit.ndim, 3)
+        assert_equal(mit.nd, 3)
         assert_equal(mit.numiter, 1)
         assert_(arrs[0] is mit.iters[0].base)