Type Error in XOR example

[sutr90]

Hi, I was testing my setup with your examples just to be sure everything works before I start doing any serious work.

When I run the example I get some log output and then following error:

  File "xor-classfier.py", line 27, in <module>
    e.run(train, train)
  File "/home/theano/dp/python/theano-nets/theanets/main.py", line 210, in run
    for _ in self.train(train=train, valid=valid):
  File "/home/theano/dp/python/theano-nets/theanets/main.py", line 238, in train
    cg_set=self.datasets['cg']):
  File "/home/theano/dp/python/theano-nets/theanets/trainer.py", line 135, in train
    self.evaluate(i, valid_set)
  File "/home/theano/dp/python/theano-nets/theanets/trainer.py", line 93, in evaluate
    costs = np.mean([self.f_eval(*x) for x in valid_set], axis=0)
  File "/usr/lib/python2.7/site-packages/theano/compile/function_module.py", line 497, in __call__
    allow_downcast=s.allow_downcast)
  File "/usr/lib/python2.7/site-packages/theano/tensor/type.py", line 119, in filter
    raise TypeError(err_msg, data)
TypeError: ('Bad input argument to theano function at index 0(0-based)', 'TensorType(float32, matrix) cannot store a value of dtype float64 without risking loss of precision. If you do not mind this loss, you can: 1) explicitly cast your data to float32, or 2) set "allow_input_downcast=True" when calling "function".', array([[ ... ]]))

I understand what's going on, I'm just not sure how to fix it.

I see two option here: either I have incorrect setup in my theano installation or there is some flaw in your code.

My setup taken from .theanorc

[global]
floatX = float32
device = gpu0
mode=FAST_RUN

[nvcc]
fastmath = True

[blas]
ldflags = -latlas -lgfortran -lf77blas

I think there is a conflict with your code and my settings, as my theano is trying to run on GPU, while yours isn't aware of it.

Thanks for help.

[lmjohns3]

Thanks for the feedback! The example needed to be told explicitly which floating-point format to use. I think Theano also lets you avoid this error by setting the allow_input_downcast keyword arg when calling functions, but I've avoided doing that in favor of making sure the data is in the format I expect.

[sutr90]

Thanks for clearing this out. I was afraind, it would affect some other parts of library too.