NotImplementedError  #2583

NotImplementedError                       Traceback (most recent call last)
<ipython-input-131-12bbb6ff2f15> in <module>()
     39         errG = criterion(output, labelv)
     40         print(errG)
---> 41         errG.backward()
     42         D_G_z2 = output.data.mean()
     43         optimizerG.step()

/usr/local/lib/python2.7/dist-packages/torch/autograd/variable.pyc in backward(self, gradient, retain_graph, create_graph, retain_variables)
    155                 Variable.
    156         """
--> 157         torch.autograd.backward(self, gradient, retain_graph, create_graph, retain_variables)
    158 
    159     def register_hook(self, hook):

/usr/local/lib/python2.7/dist-packages/torch/autograd/__init__.pyc in backward(variables, grad_variables, retain_graph, create_graph, retain_variables)
     96 
     97     Variable._execution_engine.run_backward(
---> 98         variables, grad_variables, retain_graph)
     99 
    100 

/usr/local/lib/python2.7/dist-packages/torch/autograd/function.pyc in backward(*grad_outputs)
    182         be the gradient w.r.t. the corresponding input.
    183         """
--> 184         raise NotImplementedError
    185 
    186 

NotImplementedError: