GSLInterpolator.cxx

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// @(#)root/mathmore:$Id$
// Authors: L. Moneta, A. Zsenei   08/2005
 
 /**********************************************************************
  *                                                                    *
  * Copyright (c) 2004 ROOT Foundation,  CERN/PH-SFT                   *
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  * This library is free software; you can redistribute it and/or      *
  * modify it under the terms of the GNU General Public License        *
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  * This library is distributed in the hope that it will be useful,    *
  * but WITHOUT ANY WARRANTY; without even the implied warranty of     *
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  * General Public License for more details.                           *
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  **********************************************************************/
 
// Implementation file for class GSLInterpolator
//
// Created by: moneta  at Sun Nov 28 08:54:48 2004
//
// Last update: Sun Nov 28 08:54:48 2004
//
 
#include "GSLInterpolator.h"
 
 
#include <cassert>
 
namespace ROOT {
namespace Math {
 
 
GSLInterpolator::GSLInterpolator (unsigned int size, Interpolation::Type type) :
   fResetNErrors(true),
   fAccel(nullptr),
   fSpline(nullptr)
{
   // constructor given type and vectors of (x,y) points
 
   switch ( type )
   {
      case ROOT::Math::Interpolation::kLINEAR          :
         fInterpType = gsl_interp_linear;
         break ;
      case ROOT::Math::Interpolation::kPOLYNOMIAL       :
         fInterpType = gsl_interp_polynomial;
         break ;
         // depend on GSL linear algebra
      case ROOT::Math::Interpolation::kCSPLINE         :
         fInterpType = gsl_interp_cspline ;
         break ;
      case ROOT::Math::Interpolation::kCSPLINE_PERIODIC :
         fInterpType = gsl_interp_cspline_periodic  ;
         break ;
      case ROOT::Math::Interpolation::kAKIMA            :
         fInterpType = gsl_interp_akima;
         break ;
      case ROOT::Math::Interpolation::kAKIMA_PERIODIC   :
         fInterpType = gsl_interp_akima_periodic;
         break ;
      default :
         // cspline
         fInterpType = gsl_interp_cspline;
         break ;
   }
   // allocate objects
 
   if (size >= fInterpType->min_size)
      fSpline = gsl_spline_alloc( fInterpType, size);
 
}
 
bool  GSLInterpolator::Init(unsigned int size, const double *x, const double * y) {
   // initialize interpolation object with the given data
   // if given size is different a new interpolator object is created
   if (fSpline == nullptr)
      fSpline = gsl_spline_alloc( fInterpType, size);
 
   else {
      gsl_interp * interp = fSpline->interp;
      if (size != interp->size) {
         //  free and reallocate a new object
         gsl_spline_free(fSpline);
         fSpline = gsl_spline_alloc( fInterpType, size);
 
      }
   }
   if (!fSpline) return false;
 
   int iret = gsl_spline_init( fSpline , x , y , size );
   if (iret != 0) return false;
 
   if(fAccel==nullptr)
      fAccel = gsl_interp_accel_alloc() ;
   else
      gsl_interp_accel_reset(fAccel);
 
   //  if (fSpline == 0 || fAccel == 0)
   //  throw std::exception();
   assert (fSpline != nullptr);
   assert (fAccel != nullptr);
   // reset counter for error messages
   fResetNErrors = true;
   return true;
}
 
GSLInterpolator::~GSLInterpolator()
{
   // free gsl objects
   if (fSpline != nullptr) gsl_spline_free(fSpline);
   if (fAccel != nullptr) gsl_interp_accel_free( fAccel);
}
 
} // namespace Math
} // namespace ROOT