@@ -180,7 +180,11 @@ def sympify(expr, locals=None):

                 "identifiers and may not be keywords".format(repr(k)))

     # sympify values of locals before updating it with extra_ns

-    locals = {k: sympify(v) for k, v in locals.items()}

+    # Cast numpy array values in locals to sympy matrices to make sure they have

+    # correct format

+    locals = {k: (sympy.Matrix(v) if isinstance(v, np.ndarray) else sympify(v))

+              for k, v in locals.items()}

+

     for k, v in extra_ns.items():

         locals.setdefault(k, v)

     try: