Merge pull request #1283 from mrocklin/matinv-solve

theano/sandbox/linalg/ops.py

@@ -5,7 +5,8 @@ import numpy
 
 from theano.gof import Op, Apply
 
-from theano.tensor import as_tensor_variable, dot, DimShuffle
+from theano.tensor import as_tensor_variable, dot, DimShuffle, Dot
+from theano.tensor.blas import Dot22
 from theano import tensor
 import theano.tensor
 from theano.tensor.opt import (register_stabilize,
@@ -227,7 +228,7 @@ def is_positive(v):
 def inv_as_solve(node):
     if not imported_scipy:
         return False
-    if node.op == dot:
+    if isinstance(node.op, (Dot, Dot22)):
         l, r = node.inputs
         if l.owner and l.owner.op == matrix_inverse:
             return [solve(l.owner.inputs[0], r)]

theano/sandbox/linalg/tests/test_linalg.py

@@ -28,6 +28,7 @@ from theano.sandbox.linalg.ops import (cholesky,
                                        spectral_radius_bound,
                                        imported_scipy,
                                        Eig,
+                                       inv_as_solve,
                                        )
 from theano.sandbox.linalg import eig, eigh
 from nose.plugins.skip import SkipTest
@@ -533,3 +534,10 @@ class test_Eigh(test_Eig):
 
 class test_Eigh_float32(test_Eigh):
     dtype = 'float32'
+
+def test_matrix_inverse_solve():
+    A = theano.tensor.dmatrix('A')
+    b = theano.tensor.dmatrix('b')
+    node = matrix_inverse(A).dot(b).owner
+    [out] = inv_as_solve.transform(node)
+    assert isinstance(out.owner.op, Solve)