src/mathlib_src/GDiff_Util.h

説明を見る。

#ifndef GDIFF_UTIL_H
#define GDIFF_UTIL_H

#include "GMatrix.h"

namespace GMathLib
{

namespace GDiff_Util{

inline double CentralDiff1D(double* discre_data, int no, double del_x, bool periodic_bound_condition=false, int d_size=0){
       
       if(periodic_bound_condition){  
           if(no == 0){
               return (discre_data[d_size-1] - discre_data[1])/(2 * del_x);
           }else if(no == d_size-1){
               return (discre_data[0] - discre_data[d_size-2])/(2 * del_x);
           }
       }

       return (discre_data[no+1] - discre_data[no-1])/(2 * del_x);
}




inline double Diff_2Times1D(double* discre_data, int no, double del_x, bool periodic_bound_condition=false, int d_size=0){
       
       if(periodic_bound_condition){  
           if(no == 0){
               return (discre_data[1] - 2 * discre_data[no] + discre_data[d_size-1])/(del_x * del_x);
           }else if(no == d_size-1){
               return (discre_data[0] - 2 * discre_data[d_size-1] + discre_data[d_size-2])/(del_x * del_x);
           }
       }
       
       return (discre_data[no+1] - 2 * discre_data[no] + discre_data[no-1])/(del_x * del_x);
}


inline void BoundaryCondition2D_For_MatrixId(
         int i, int j, int &iup, int &idown, int &jup, int &jdown, int matrix_isize, int matrix_jsize
         )
{
     //インデックス i について調整する
     if(i == 0){
        idown = matrix_isize-1;
        iup = i+1;
     }else if(i == matrix_isize-1){
        iup = 0;
        idown=i-1;
     }else{
        iup = i+1;
        idown = i-1;
     }
                   
     if(j == 0){
         jdown = matrix_jsize-1;
         jup = j+1;
     }else if(j == matrix_jsize-1){
         jup = 0;
         jdown = j-1;
     }else{
         jup = j+1;
         jdown = j-1;
     }     
}

} //end namespace GDiff_Util
} //end namespace GMathLib
#endif

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