Merge changes mistakenly added to 1.0b4 tag to the main trunk

1 files changed, 42 insertions, 1 deletions

diff --git a/numpy/core/numeric.py b/numpy/core/numeric.py
index b77fed3db..b89fc0586 100644
--- a/numpy/core/numeric.py
+++ b/numpy/core/numeric.py
@@ -7,7 +7,7 @@ __all__ = ['newaxis', 'ndarray', 'flatiter', 'ufunc',
            'asarray', 'asanyarray', 'ascontiguousarray', 'asfortranarray',
            'isfortran', 'empty_like', 'zeros_like',
            'correlate', 'convolve', 'inner', 'dot', 'outer', 'vdot',
-           'alterdot', 'restoredot', 'cross',
+           'alterdot', 'restoredot', 'cross', 'tensordot',
            'array2string', 'get_printoptions', 'set_printoptions',
            'array_repr', 'array_str', 'set_string_function',
            'little_endian', 'require',
@@ -252,6 +252,47 @@ except ImportError:
     def restoredot():
         pass
 
+def tensordot(a, b, axes=(-1,0))
+    """tensordot returns the product for any (ndim >= 1) arrays.
+
+    r_{xxx, yyy} = \sum_k a_{xxx,k} b_{k,yyy} where
+
+    the axes to be summed over are given by the axes argument.
+    the first element of the sequence determines the axis or axes
+    in arr1 to sum over and the second element in axes argument sequence
+    """
+    axes_a, axes_b = axes
+    try:
+        na = len(axes_a)
+    except TypeError:
+        axes_a = [axes_a]
+        na = 1
+    try:
+        nb = len(axes_b)
+    except TypeError:
+        axes_b = [axes_b]
+        nb = 1
+
+    a, b = asarray(a), asarray(b)
+    as = a.shape
+    bs = b.shape
+    equal = 1
+    if (na != nb): equal = 0
+    for k in xrange(na):
+        if as[axes_a[k]] != bs[axes_b[k]]:
+            equal = 0
+            break
+
+    if not equal:
+        raise ValueError, "shape-mismatch for sum"    
+    
+    olda = [ for k in aa if k not in axes_a]
+    oldb = [k for k in bs if k not in axes_b]
+
+    at = a.reshape(nd1, nd2)
+    res = dot(at, bt)
+    return res.reshape(olda + oldb)
+
 
 def _move_axis_to_0(a, axis):
     if axis == 0: