mirror of
https://github.com/paboyle/Grid.git
synced 2024-11-14 01:35:36 +00:00
46 lines
1.4 KiB
C
46 lines
1.4 KiB
C
|
#ifndef GRID_MATH_DET_H
|
||
|
|
#define GRID_MATH_DET_H
|
||
|
|
namespace Grid {
|
||
|
|
///////////////////////////////////////////////
|
||
|
|
// Determinant function for scalar, vector, matrix
|
||
|
|
///////////////////////////////////////////////
|
||
|
|
inline ComplexF Determinant( const ComplexF &arg){ return arg;}
|
||
|
|
inline ComplexD Determinant( const ComplexD &arg){ return arg;}
|
||
|
|
inline RealF Determinant( const RealF &arg){ return arg;}
|
||
|
|
inline RealD Determinant( const RealD &arg){ return arg;}
|
||
|
|
|
||
|
|
template<class vtype> inline auto Determinant(const iScalar<vtype>&r) -> iScalar<decltype(Determinant(r._internal))>
|
||
|
|
{
|
||
|
|
iScalar<decltype(Determinant(r._internal))> ret;
|
||
|
|
ret._internal = Determinant(r._internal);
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
template<class vtype,int N, typename std::enable_if< GridTypeMapper<vtype>::TensorLevel == 0 >::type * =nullptr>
|
||
|
|
inline iScalar<vtype> Determinant(const iMatrix<vtype,N> &arg)
|
||
|
|
{
|
||
|
|
iMatrix<vtype,N> ret(arg);
|
||
|
|
iScalar<vtype> det = vtype(1.0);
|
||
|
|
/* Conversion of matrix to upper triangular */
|
||
|
|
for(int i = 0; i < N; i++){
|
||
|
|
for(int j = 0; j < N; j++){
|
||
|
|
if(j>i){
|
||
|
|
vtype ratio = ret._internal[j][i]/ret._internal[i][i];
|
||
|
|
for(int k = 0; k < N; k++){
|
||
|
|
ret._internal[j][k] -= ratio * ret._internal[i][k];
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
for(int i = 0; i < N; i++)
|
||
|
|
det *= ret._internal[i][i];
|
||
|
|
|
||
|
|
return det;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
}
|
||
|
|
#endif
|