Also, never ignore the updates returned by theano.scan! In other words, always do:
result, updates = theano.scan(...) f = theano.function(..., updates=updates) and never: result, _ = theano.scan(...) On Thu, Sep 29, 2016, 杨培 wrote: > When I use theano loop with RandomStream to generate random number， > theano compile fail with “MissingInput”。 > > I Google this problem， and I found ： > > - a issue（https://github.com/Theano/Theano/issues/3437）。This issue said > we cannot use RandomStream with symbolic shape in scan。 > > But I also found ： > > - a documentation int Theano > > （http://deeplearning.net/software/theano/library/scan.html#using-shared-variables-gibbs-sampling），the > > code in the documentation use RandomStream with symbolic shape in scan。 > > So，how to use theano scan with RandomStream。Thanks for your help > > here is my code。this code compile failed > > > - import theano; > - from theano import tensor as T; > - import numpy as np; > - > - from theano.sandbox.rng_mrg import MRG_RandomStreams as RandomStreams; > - > - x=T.ivector(); > - > - def step(i): > - sample=RandomStreams().binomial(size=(i,)); > - return sample; > - > - result,_=theano.scan(fn=step,outputs_info=None, > - sequences=[x]); > - > - f=theano.function([x],result); > - > - x_val=np.array([1,2,3],dtype='int32'); > - print f(x_val); > > > this code work fine > > - import theano; > - from theano import tensor as T; > - import numpy as np; > - > - from theano.sandbox.rng_mrg import MRG_RandomStreams as RandomStreams; > - > - x=T.ivector(); > - len=x.shape[0]; > - > - def step(i): > - len_=len; > - sample=RandomStreams().binomial(size=(len_,)); > - return sample; > - > - result,_=theano.scan(fn=step,outputs_info=None, > - sequences=[x]); > - > - f=theano.function([x],result); > - > > > - x_val=np.array([1,2,3],dtype='int32'); > - print f(x_val); > > > > > > -- > > --- > You received this message because you are subscribed to the Google Groups > "theano-users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to theano-users+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. -- Pascal -- --- You received this message because you are subscribed to the Google Groups "theano-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to theano-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
