Added Eig.grad stub

theano/sandbox/linalg/ops.py

@@ -12,7 +12,8 @@ from theano.tensor.opt import (register_stabilize,
         register_specialize, register_canonicalize)
 from theano.gof import local_optimizer
 from theano.gof.opt import Optimizer
-
+from theano.gradient import grad_not_implemented
+1
 try:
     import scipy.linalg
     imported_scipy = True
@@ -918,4 +919,12 @@ class Eig(Op):
     def __str__(self):
         return "Eig"
 
+    def grad(self, (x,), g_outputs):
+        """The gradient function should return :math:`dw, dv`, where
+
+            .. math:: dw = ...
+            .. math:: dv = ...
+        """
+        return [grad_not_implemented(self, 0, x, "Work in progress.")]
+
 eig = Eig()