Save cifar whitening tensor to disk and reload if available, rather than recomputing
global L1 scaling 0.5 (cifar-specific), softmax scaling for entropy 0.875, L1 scaling 8, entropy scaling 3,
200 units, 16 ista iterations, 1 regularization iterations
learning rate 5e-3, minibatch size 10, 1000 epochs pretraining
decoding_feature_extraction_dictionary rows are fully normalized