SimplexParameters.cxx

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// @(#)root/minuit2:$Id$
// Authors: M. Winkler, F. James, L. Moneta, A. Zsenei   2003-2005

/**********************************************************************
 *                                                                    *
 * Copyright (c) 2005 LCG ROOT Math team,  CERN/PH-SFT                *
 *                                                                    *
 **********************************************************************/

#include "Minuit2/SimplexParameters.h"

namespace ROOT {

   namespace Minuit2 {


void SimplexParameters::Update(double y, const MnAlgebraicVector& p) {
   // update the SimplexParameter object with a new value y = FCN(p)
   fSimplexParameters[Jh()] = std::pair<double, MnAlgebraicVector>(y, p);
   if(y < fSimplexParameters[Jl()].first) fJLow = Jh();

   unsigned int jh = 0;
   for(unsigned int i = 1; i < fSimplexParameters.size(); i++) {
      if(fSimplexParameters[i].first > fSimplexParameters[jh].first) jh = i;
   }
   fJHigh = jh;

   return;
}

MnAlgebraicVector SimplexParameters::Dirin() const {
   // find simplex direction (vector from big to smaller parameter points)
   MnAlgebraicVector dirin(fSimplexParameters.size() - 1);
   for(unsigned int i = 0; i < fSimplexParameters.size() - 1; i++) {
      double pbig = fSimplexParameters[0].second(i), plit = pbig;
      for(unsigned int j = 0; j < fSimplexParameters.size(); j++){
         if(fSimplexParameters[j].second(i) < plit) plit = fSimplexParameters[j].second(i);
         if(fSimplexParameters[j].second(i) > pbig) pbig = fSimplexParameters[j].second(i);
      }
      dirin(i) = pbig - plit;
   }

   return dirin;
}

   }  // namespace Minuit2

}  // namespace ROOT