memory warning

[euhruska]

in the vampnet examples

hist = model.fit([X1_train, X2_train], Y_train ,
                         batch_size=batch_size,
                         epochs=nb_epoch,
                         validation_data=([X1_vali, X2_vali], Y_vali ),
                         verbose=0)

leads to

tensorflow/python/ops/gradients_impl.py:108: UserWarning: Converting sparse IndexedSlices to a dense Tensor of unknown shape. This may consume a large amount of memory.
  "Converting sparse IndexedSlices to a dense Tensor of unknown shape. "

It's just a warning, but might affect the performance

[amardt]

Hey,

I think the reason for the warning is the slicing of the eigenvalues and -vectors in the _inv function. I don't think that this will cause performance loss, but I changed the code to avoid this. We have to test it first, though. See #18

Best,

Andreas