PowerVariogram.cpp

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#ifdef HAVE_CONFIG_H
   #include <config.h>
#else
#error "Cannot compile with HAVE_CONFIG_H symbol! run configure first!"
#endif
 
#include "../classes.h"
#include "../../shared/shared.h"
 
/*PowerVariogram constructors and destructor*/
PowerVariogram::PowerVariogram(){/*{{{*/
   this->nugget = 0.2;
   this->slope  = 1.;
   this->power  = 1.;
   return;
}
/*}}}*/
PowerVariogram::PowerVariogram(Options* options){/*{{{*/
 
   /*Defaults*/
   this->nugget = 0.2;
   this->slope  = 1.;
   this->power  = 1.;
 
   /*Overwrite from options*/
   if(options->GetOption("nugget")) options->Get(&this->nugget,"nugget");
   if(options->GetOption("slope"))  options->Get(&this->slope,"slope");
   if(options->GetOption("power"))  options->Get(&this->power,"power");
 
   /*Checks*/
   if(power<=0 || power>=2) _error_("power must be betwwen 0 and 2 (0 < power < 2)");
   if(slope<=0) _error_("slope must be positive");
}
/*}}}*/
PowerVariogram::~PowerVariogram(){/*{{{*/
   return;
}
/*}}}*/
 
/*Object virtual functions definitions:*/
Object* PowerVariogram::copy(void){/*{{{*/
      return new PowerVariogram(*this);
}
/*}}}*/
void PowerVariogram::Echo(void){/*{{{*/
   _printf_("PowerVariogram\n");
   _printf_("   nugget: " << this->nugget << "\n");
   _printf_("   slope : " << this->slope << "\n");
   _printf_("   power : " << this->power << "\n");
}
/*}}}*/
 
/*Variogram function*/
double PowerVariogram::Covariance(double deltax,double deltay){/*{{{*/
   /*The covariance can be deduced from the variogram from the following
    * relationship:
    *    2 gamma = C(x,x) + C(y,y) -2 C(x,y)
    * so
    *    C(h) = sill - gamma                                            */
   double h,cova;
 
   /*Calculate length square*/
   h=sqrt(deltax*deltax + deltay*deltay);
 
   /*return covariance*/
   cova = 9999. - this->slope*pow(h,this->power);
 
   return cova;
}
/*}}}*/
double PowerVariogram::SemiVariogram(double deltax,double deltay){/*{{{*/
   /*http://en.wikipedia.org/wiki/Variogram*/
   double h,gamma;
 
   /*Calculate length square*/
   h=sqrt(deltax*deltax + deltay*deltay);
 
   /*return semi-variogram*/
   gamma = this->nugget + this->slope*pow(h,this->power);
 
   //if(h>1000) _printf_("gamma = " << gamma << " h=" << h << "\n");
   return gamma;
}
/*}}}*/