Made tensordot interface the same as the documentation.

theano/tensor/basic.py

@@ -3841,19 +3841,7 @@ pprint.assign(dot, printing.OperatorPrinter(printing.special['middle_dot'], -1,
 #########################
 class TensorDotGrad(Op):
     def __init__(self, axes):
-        if isinstance(axes,list):
-            for i,a in enumerate(axes):
-                if isinstance(a,list):
-                    axes[i]=tuple(a)
-            axes=tuple(axes)
-        if isinstance(axes, tuple):
-            if len(axes)!=2:
-                raise ValueError("We need the list/tuple of axes to be of length 2")
-            if len(axes[0])!=len(axes[1]):
-                raise ValueError("We need that the axes 2 sub list of axes are of the same size")
-            assert len(axes[0])==len(axes[1])
-
-        self.axes = axes;
+        self.axes = TensorDot.parse_axes(axes)
 
     def __eq__(self, other):
         return type(self) == type(other) and self.axes == other.axes
@@ -3903,20 +3891,31 @@ class TensorDot(Op):
 
     """
 
-    def __init__(self, axes):
-        if isinstance(axes,list):
+    @classmethod
+    def parse_axes(cls, axes):
+
+        if not numpy.isscalar(axes) and len(axes)!=2:
+            raise ValueError("Axes should be scalar valued or a list/tuple of len 2.")
+
+        if isinstance(axes,(list,tuple)):
+            axes_out = []
+            # cast axes[0] and axes[1] to tuples
             for i,a in enumerate(axes):
-                if isinstance(a,list):
-                    axes[i]=tuple(a)
-            axes=tuple(axes)
-        if isinstance(axes, tuple):
-            if len(axes)!=2:
-                raise ValueError("We need the list/tuple of axes to be of length 2")
-            if len(axes[0])!=len(axes[1]):
-                raise ValueError("We need that the axes 2 sub list of axes are of the same size")
-            assert len(axes[0])==len(axes[1])
-
-        self.axes = axes
+                if numpy.isscalar(a):
+                    axes_out.append((a,))
+                else:
+                    axes_out.append(tuple(a))
+
+            # these should be of same length
+            if len(axes_out[0])!=len(axes_out[1]):
+                raise ValueError("Elements of the axes list/tuple need to be of the same size.")
+
+            axes = tuple(axes_out)
+
+        return axes
+
+    def __init__(self, axes):
+        self.axes = self.parse_axes(axes)
 
     def __eq__(self, other):
         return type(self) == type(other) and self.axes == other.axes
@@ -3957,7 +3956,40 @@ class TensorDot(Op):
 
     def __str__(self):
         return "tensordot"
-tensordot = TensorDot
+
+def tensordot(x, y, axes=2):
+    if x.ndim==0 or y.ndim==0:
+        raise ValueError('Cannot perform tensordot of 0-d inputs.')
+
+    axes = TensorDot.parse_axes(axes)
+    
+    # check whether axes is valid given the dimensions of x and y
+    if numpy.isscalar(axes):
+        if axes >= x.ndim or axes >= y.ndim:
+            raise ValueError('axes should be smaller than the dimension of '\
+                    'x and y (x.ndim=%i, y.ndim=%i)' % (x.ndim,y.ndim))
+    elif isinstance(axes, (list,tuple)):
+
+        if isinstance(axes[0],(list,tuple)) and \
+           (len(axes[0]) > x.ndim or (numpy.array(axes[0]) >= x.ndim).any()):
+            raise ValueError('axes[0] should be array_like, of length smaller'\
+                    ' than the dimension of x (x.ndim=%i, len(axes[0])=%i).' %
+                    (x.ndim, len(axes[0])))
+
+        if isinstance(axes[1],(list,tuple)) and \
+           (len(axes[1]) > y.ndim or (numpy.array(axes[1]) >= y.ndim).any()):
+            raise ValueError('axes[1] should be array_like, of length smaller'\
+                    'than the dimension of y (y.ndim=%i, len(axes[1])=%i).' % 
+                    (y.ndim, len(axes[1])))
+
+    if not hasattr(tensordot, 'op'):
+        tensordot.op = {}
+    
+    if axes not in tensordot.op:
+        tensordot.op[axes] = TensorDot(axes)
+
+    return tensordot.op[axes](x, y)
+
 
 #TODO: tensordot should be function as described in rst docs.
 

theano/tensor/tests/test_basic.py

@@ -2920,7 +2920,7 @@ class test_tensordot(unittest.TestCase):
         avec = vector()
         bvec = vector()
         axes = ((0,),(0,))
-        c = tensordot(axes)(avec, bvec)
+        c = tensordot(avec, bvec, axes)
         f1 = inplace_func([avec,bvec],c)
         aval = self.rand(5);
         bval = self.rand(5);
@@ -2931,7 +2931,7 @@ class test_tensordot(unittest.TestCase):
         # test matrix-vector
         bmat = matrix()
         axes = ((0,),(1,))
-        c = tensordot(axes)(avec, bmat)
+        c = tensordot(avec, bmat, axes)
         f2 = inplace_func([avec,bmat],c)
         aval = self.rand(5);
         bval = self.rand(8,5);
@@ -2942,7 +2942,7 @@ class test_tensordot(unittest.TestCase):
         # test matrix-matrix
         amat = matrix()
         axes = ((1,),(0,))
-        c = tensordot(axes)(amat, bmat)
+        c = tensordot(amat, bmat, axes)
         f3 = inplace_func([amat,bmat],c)
         aval = self.rand(4,7);
         bval = self.rand(7,9);
@@ -2953,7 +2953,7 @@ class test_tensordot(unittest.TestCase):
         # test ndarray-matrix, sum over one dim of matrix
         atens = tensor4()
         axes = ((2,),(1,))
-        c = tensordot(axes)(atens, bmat)
+        c = tensordot(atens, bmat, axes)
         f4 = inplace_func([atens,bmat],c)
         aval = self.rand(1,2,3,4);
         bval = self.rand(2,3);
@@ -2965,7 +2965,7 @@ class test_tensordot(unittest.TestCase):
         atens = tensor4()
         btens = tensor3()
         axes = ((1,3),(0,2))
-        c = tensordot(axes)(atens, btens)
+        c = tensordot(atens, btens, axes)
         f5 = inplace_func([atens,btens],c)
         aval = self.rand(4,3,5,2);
         bval = self.rand(3,4,2);
@@ -2974,47 +2974,59 @@ class test_tensordot(unittest.TestCase):
         utt.verify_grad(TensorDot(axes), [aval,bval])
 
         axes = (axes[1],axes[0])
-        c = tensordot(axes)(btens, atens)
+        c = tensordot(btens, atens, axes)
         f6 = inplace_func([btens,atens],c)
         self.failUnless(numpy.allclose(numpy.tensordot(bval,aval,axes),
                                        f6(bval,aval)))
         utt.verify_grad(TensorDot(axes), [bval,aval])
 
     def test_raise_error(self):
-
-        # test vector-vector
-        avec = vector()
+        amat = matrix()
+        bmat = matrix()
         bvec = vector()
-        axes = ((0,),())
+
+        # test invalid length for axes
         try:
-            c = tensordot(axes)(avec, bvec)
+            c = tensordot(amat, bmat, (0,1,2))
             assert False
         except ValueError:
             pass
-        # test matrix-vector
-        bmat = matrix()
-        axes = ((0,),())
+
+        # test axes of uneven length
         try:
-            c = tensordot(axes)(avec, bmat)
+            c = tensordot(amat, bmat, ((0,1),(0)))
             assert False
         except ValueError:
             pass
 
-        # test matrix-matrix
-        amat = matrix()
-        axes = ((1,),())
+        # test invalid len(axes) given inputs are matrices
         try:
-            c = tensordot(axes)(amat, bmat)
+            c = tensordot(amat, bmat, ((0,1,2),(0,1,2)))
             assert False
         except ValueError:
             pass
 
-    def test_list(self):
+        # test invalid axes[1] given that y is a vector
+        try:
+            c = tensordot(amat, bvec, (0,1))
+            assert False
+        except ValueError:
+            pass
+
+        # test invalid scalar axes given inputs are matrices
+        try:
+            c = tensordot(amat, bvec, 2)
+            assert False
+        except ValueError:
+            pass
+
+
+    def test_weird_valid_axes(self):
         # test matrix-matrix
         amat = matrix()
         bmat = matrix()
-        axes = [[1,],[0,]]
-        c = tensordot(axes)(amat, bmat)
+        for axes in 0, (1,0), [1,0], (1,(0,)), ((1,),0), ([1],[0]):
+            c = tensordot(amat, bmat, axes)
             f3 = inplace_func([amat,bmat],c)
             aval = self.rand(4,7);
             bval = self.rand(7,9);
@@ -3022,14 +3034,14 @@ class test_tensordot(unittest.TestCase):
                                            f3(aval,bval)))
             utt.verify_grad(TensorDot(axes), [aval,bval])
 
-    def test_scalar(self):
+    def test_scalar_axes(self):
         # test matrix-matrix
         amat = fmatrix()
         bmat = dmatrix()#we let at float64 to test mix of float32 and float64.
         axes = 1
         aval = self.rand(4,5)
         bval = numpy.random.rand(5,3)
-        c = tensordot(axes)(amat, bmat)
+        c = tensordot(amat, bmat, axes)
         f3 = inplace_func([amat,bmat],c)
         self.failUnless(numpy.allclose(numpy.tensordot(aval,bval,axes),
                                        f3(aval,bval)))
@@ -3041,7 +3053,7 @@ class test_tensordot(unittest.TestCase):
         axes = 2
         aval = self.rand(3,4,5)
         bval = self.rand(4,5,3)
-        c = tensordot(axes)(amat, bmat)
+        c = tensordot(amat, bmat, axes)
         f3 = inplace_func([amat,bmat],c)
         self.failUnless(numpy.allclose(numpy.tensordot(aval,bval,axes),
                                        f3(aval,bval)))
@@ -3054,7 +3066,7 @@ class test_tensordot(unittest.TestCase):
         axes = 0
         aval = self.rand(4,5)
         bval = self.rand(5,4)
-        c = tensordot(axes)(amat, bmat)
+        c = tensordot(amat, bmat, axes)
         f3 = inplace_func([amat,bmat],c)
         self.failUnless(numpy.allclose(numpy.tensordot(aval,bval,axes),
                                        f3(aval,bval)))