ConvexBasisKernel.cc

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// -*- C++ -*-

// PLearn (A C++ Machine Learning Library)
// Copyright (C) 1998 Pascal Vincent
// Copyright (C) 1999-2002 Pascal Vincent, Yoshua Bengio, Rejean Ducharme and University of Montreal
// Copyright (C) 2001-2002 Nicolas Chapados, Ichiro Takeuchi, Jean-Sebastien Senecal
// Copyright (C) 2002 Xiangdong Wang, Christian Dorion

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// modification, are permitted provided that the following conditions are met:
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/* *******************************************************      
   * $Id: ConvexBasisKernel.cc,v 1.4 2004/04/07 23:15:58 morinf Exp $
   * This file is part of the PLearn library.
   ******************************************************* */

#include "ConvexBasisKernel.h"

namespace PLearn {
using namespace std;



PLEARN_IMPLEMENT_OBJECT(ConvexBasisKernel, "ONE LINE DESCR", "NO HELP");
real ConvexBasisKernel::evaluate(const Vec& x1, const Vec& x2) const
{ 
  real p=1;
  real* x1i=x1.data();
  real* x2i=x2.data();
  int n=x1.length();
  for (int i=0;i<n;i++)
    p *= log(1+exp(c*(x1i[i]-x2i[i])));
  return p;
}

void ConvexBasisKernel::declareOptions(OptionList &ol)
{
    declareOption(ol, "c", &ConvexBasisKernel::c, OptionBase::buildoption,
                  "TODO: Some comments");
    inherited::declareOptions(ol);
}



} // end of namespace PLearn

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