// nnet2/mixup-nnet.h

// Copyright 2012  Johns Hopkins University (author: Daniel Povey)

// See ../../COPYING for clarification regarding multiple authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//  http://www.apache.org/licenses/LICENSE-2.0
//
// THIS CODE IS PROVIDED *AS IS* BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED
// WARRANTIES OR CONDITIONS OF TITLE, FITNESS FOR A PARTICULAR PURPOSE,
// MERCHANTABLITY OR NON-INFRINGEMENT.
// See the Apache 2 License for the specific language governing permissions and
// limitations under the License.

#ifndef KALDI_NNET2_MIXUP_NNET_H_
#define KALDI_NNET2_MIXUP_NNET_H_

#include "nnet2/nnet-update.h"
#include "nnet2/nnet-compute.h"
#include "itf/options-itf.h"

namespace kaldi {
namespace nnet2 {

struct NnetMixupConfig {
  BaseFloat power;
  BaseFloat min_count;
  int32 num_mixtures;
  BaseFloat perturb_stddev;
  
  
  NnetMixupConfig(): power(0.25), min_count(1000.0),
                     num_mixtures(-1), perturb_stddev(0.01) { }
  
  void Register(OptionsItf *po) {
    po->Register("power", &power, "Scaling factor used in determining the "
                 "number of mixture components to use for each HMM state "
                 "(or group of HMM states)");
    po->Register("min-count", &min_count, "Minimum count for a quasi-Gaussian, "
                 "enforced while allocating mixtures (obscure parameter).");
    po->Register("num-mixtures", &num_mixtures, "If specified, total number of "
                 "mixture components to mix up to (should be at least the "
                 "#leaves in the system");
    po->Register("perturb-stddev", &perturb_stddev, "Standard deviation used "
                 "when perturbing parameters during mixing up");
  }  
};

/**
  This function does something similar to Gaussian mixture splitting for
  GMMs, except applied to the output layer of the neural network.
  We create additional outputs, which will be summed over using a
  SumGroupComponent.
*/

void MixupNnet(const NnetMixupConfig &mixup_config,
               Nnet *nnet);
  


} // namespace nnet2
} // namespace kaldi

#endif