text: /*
   * Copyright (c) The Shogun Machine Learning Toolbox
   * Written (w) 2015 Wu Lin
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * 1. Redistributions of source code must retain the above copyright notice, this
   *    list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright notice,
   *    this list of conditions and the following disclaimer in the documentation
   *    and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
   * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
   * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   *
   * The views and conclusions contained in the software and documentation are those
   * of the authors and should not be interpreted as representing official policies,
   * either expressed or implied, of the Shogun Development Team.
   *
   */
  
  #include <shogun/optimization/StandardMomentumCorrection.h>
  using namespace shogun;
  
  DescendPair StandardMomentumCorrection::get_corrected_descend_direction(float64_t negative_descend_direction,
  	index_t idx)
  {
  	REQUIRE(idx>=0 && idx<m_previous_descend_direction.vlen,"The index (%d) is invalid\n", idx);
  	DescendPair pair;
  	m_previous_descend_direction[idx]=
  		m_weight*m_previous_descend_direction[idx]-negative_descend_direction;
  	pair.delta=m_previous_descend_direction[idx];
  	pair.descend_direction=m_previous_descend_direction[idx];
  	return pair;
  }
  
  void StandardMomentumCorrection::init()
  {
  	m_weight=0.9;
  }
  
  