95 lines
3.8 KiB
C++
95 lines
3.8 KiB
C++
/********************************************************
|
|
* ██████╗ ██████╗████████╗██╗
|
|
* ██╔════╝ ██╔════╝╚══██╔══╝██║
|
|
* ██║ ███╗██║ ██║ ██║
|
|
* ██║ ██║██║ ██║ ██║
|
|
* ╚██████╔╝╚██████╗ ██║ ███████╗
|
|
* ╚═════╝ ╚═════╝ ╚═╝ ╚══════╝
|
|
* Geophysical Computational Tools & Library (GCTL)
|
|
*
|
|
* Copyright (c) 2023 Yi Zhang (yizhang-geo@zju.edu.cn)
|
|
*
|
|
* GCTL is distributed under a dual licensing scheme. You can redistribute
|
|
* it and/or modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation, either version 2
|
|
* of the License, or (at your option) any later version. You should have
|
|
* received a copy of the GNU Lesser General Public License along with this
|
|
* program. If not, see <http://www.gnu.org/licenses/>.
|
|
*
|
|
* If the terms and conditions of the LGPL v.2. would prevent you from using
|
|
* the GCTL, please consider the option to obtain a commercial license for a
|
|
* fee. These licenses are offered by the GCTL's original author. As a rule,
|
|
* licenses are provided "as-is", unlimited in time for a one time fee. Please
|
|
* send corresponding requests to: yizhang-geo@zju.edu.cn. Please do not forget
|
|
* to include some description of your company and the realm of its activities.
|
|
* Also add information on how to contact you by electronic and paper mail.
|
|
******************************************************/
|
|
|
|
#include "variogram.h"
|
|
#include "cmath"
|
|
|
|
bool gctl::variogram_model::valid()
|
|
{
|
|
if (nugget <= 0.0 || sill <= 0.0 || range <= 0.0) return false;
|
|
if (sill <= nugget) return false;
|
|
return true;
|
|
}
|
|
|
|
double gctl::spherical_variogram(const double &d, const variogram_model &vm)
|
|
{
|
|
if (d > vm.range) return vm.sill;
|
|
return vm.nugget + ((vm.sill-vm.nugget) * ((3.0*d)/(2.0*vm.range) - (d*d*d)/(2.0*vm.range*vm.range*vm.range)));
|
|
}
|
|
|
|
double gctl::exponential_variogram(const double &d, const variogram_model &vm)
|
|
{
|
|
return vm.nugget + ((vm.sill-vm.nugget) * (1.0-exp((-d/vm.range))));
|
|
}
|
|
|
|
double gctl::gaussian_variogram(const double &d, const variogram_model &vm)
|
|
{
|
|
double e = d/vm.range;
|
|
return vm.nugget + ((vm.sill-vm.nugget) * (1.0-exp(-1.0*e*e)));
|
|
}
|
|
|
|
double gctl::wave_variogram(const double &d, const variogram_model &vm)
|
|
{
|
|
if (d == 0.0) return vm.nugget;
|
|
|
|
double e = d/vm.range;
|
|
return vm.nugget + ((vm.sill-vm.nugget) * (1.0-sin(e)/e));
|
|
}
|
|
|
|
double gctl::rational_quadratic_variogram(const double &d, const variogram_model &vm)
|
|
{
|
|
double e = (d*d)/(vm.range*vm.range);
|
|
return vm.nugget + ((vm.sill-vm.nugget) * (e/(1.0+e)));
|
|
}
|
|
|
|
double gctl::circular_variogram(const double &d, const variogram_model &vm)
|
|
{
|
|
if(d > vm.range) return vm.sill;
|
|
|
|
double e = d/vm.range;
|
|
double p = 2.0/GCTL_Pi;
|
|
double r = sqrt(1.0-e*e);
|
|
return vm.nugget + ((vm.sill-vm.nugget) * (1-p*acos(e)+p*e*r));
|
|
}
|
|
|
|
double gctl::linear_variogram(const double &d, const variogram_model &vm)
|
|
{
|
|
if (d >= vm.range) return vm.sill;
|
|
return vm.nugget + (vm.sill-vm.nugget)*d/vm.range;
|
|
}
|
|
|
|
double gctl::variogram(const double &d, const variogram_model &vm, variogram_type_e type)
|
|
{
|
|
if (type == SPHERICAL) return spherical_variogram(d, vm);
|
|
else if (type == EXPONENTIAL) return exponential_variogram(d, vm);
|
|
else if (type == GAUSSIAN) return gaussian_variogram(d, vm);
|
|
else if (type == WAVE) return wave_variogram(d, vm);
|
|
else if (type == RATIONAL_Q) return rational_quadratic_variogram(d, vm);
|
|
else if (type == CIRCULAR) return circular_variogram(d, vm);
|
|
else if (type == LINEAR) return linear_variogram(d, vm);
|
|
return 0.0;
|
|
} |