tessem.cc

Go to the documentation of this file.

/* Copyright (C) 2016
   Oliver Lemke <olemke@core-dump.info>

   This program is free software; you can redistribute it and/or modify it
   under the terms of the GNU General Public License as published by the
   Free Software Foundation; either version 2, or (at your option) any
   later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
   USA.
*/

#include "tessem.h"
#include "file.h"
#include "matpackI.h"
#include "mystring.h"

void tessem_read_ascii(std::ifstream& is, TessemNN& net) {
  is >> net.nb_inputs >> net.nb_cache >> net.nb_outputs;

  net.b1.resize(net.nb_cache);
  for (Index i = 0; i < net.nb_cache; i++) is >> net.b1[i];

  net.b2.resize(net.nb_outputs);
  for (Index i = 0; i < net.nb_outputs; i++) is >> net.b2[i];

  net.w1.resize(net.nb_cache, net.nb_inputs);
  for (Index i = 0; i < net.nb_cache; i++)
    for (Index j = 0; j < net.nb_inputs; j++) is >> net.w1(i, j);

  net.w2.resize(net.nb_outputs, net.nb_cache);
  for (Index i = 0; i < net.nb_outputs; i++)
    for (Index j = 0; j < net.nb_cache; j++) is >> net.w2(i, j);

  net.x_min.resize(net.nb_inputs);
  for (Index i = 0; i < net.nb_inputs; i++) is >> net.x_min[i];

  net.x_max.resize(net.nb_inputs);
  for (Index i = 0; i < net.nb_inputs; i++) is >> net.x_max[i];

  net.y_min.resize(net.nb_outputs);
  for (Index i = 0; i < net.nb_outputs; i++) is >> net.y_min[i];

  net.y_max.resize(net.nb_outputs);
  for (Index i = 0; i < net.nb_outputs; i++) is >> net.y_max[i];
}

void tessem_prop_nn(VectorView& ny, const TessemNN& net, ConstVectorView nx) {
  if (nx.nelem() != net.nb_inputs) {
    ostringstream os;
    os << "Tessem NN requires " << net.nb_inputs
       << " values, but input vector has " << nx.nelem() << " element.";
    throw std::runtime_error(os.str());
  }

  if (ny.nelem() != net.nb_outputs) {
    ostringstream os;
    os << "Tessem NN generates " << net.nb_outputs
       << " values, but output vector has " << ny.nelem() << " element.";
    throw std::runtime_error(os.str());
  }

  // preprocessing
  Vector new_x(nx);
  new_x[0] *= 1e-9;
  new_x[4] *= 1e3;
  for (Index i = 0; i < net.nb_inputs; i++)
    new_x[i] =
        -1. + (new_x[i] - net.x_min[i]) / (net.x_max[i] - net.x_min[i]) * 2;

  // propagation
  Vector trans = net.b1;
  for (Index i = 0; i < net.nb_cache; i++) {
    for (Index j = 0; j < net.nb_inputs; j++)
      trans[i] += net.w1(i, j) * new_x[j];

    trans[i] = 2. / (1. + exp(-2. * trans[i])) - 1.;
  }

  Vector new_y = net.b2;
  for (Index i = 0; i < net.nb_outputs; i++) {
    for (Index j = 0; j < net.nb_cache; j++)
      new_y[i] += net.w2(i, j) * trans[j];
  }

  // postprocessing
  for (Index i = 0; i < net.nb_outputs; i++)
    ny[i] = net.y_min[i] + (new_y[i] + 1.) / 2. * (net.y_max[i] - net.y_min[i]);
}