// calculates the inverse of the matrix M outputs to M_1 //
int
inverse( GLU_complex M_1[ NCNC ] ,
const GLU_complex M[ NCNC ] )
{
#if (defined HAVE_LAPACKE_H)
const int n = NC , lda = NC ;
int ipiv[ NC + 1 ] ;
memcpy( M_1 , M , NCNC * sizeof( GLU_complex ) ) ;
int info = LAPACKE_zgetrf( LAPACK_ROW_MAJOR , n , n , M_1 , lda , ipiv ) ;
info = LAPACKE_zgetri( LAPACK_ROW_MAJOR , n , M_1 , lda, ipiv ) ;
return info ;
#elif (defined CLASSICAL_ADJOINT_INV)
// define the adjunct //
GLU_complex adjunct[ NCNC ] GLUalign ;
register GLU_complex deter = cofactor_transpose( adjunct , M ) ;
// here we worry about numerical stability //
if( cabs( deter ) < NC * PREC_TOL ) {
fprintf( stderr , "[INVERSE] Matrix is singular !!! "
"deter=%1.14e %1.14e \n" , creal( deter ) , cimag( deter ) ) ;
write_matrix( M ) ;
return GLU_FAILURE ;
}
// obtain inverse of M from 1/( detM )*adj( M ) //
size_t i ;
deter = 1.0 / deter ;
for( i = 0 ; i < NCNC ; i++ ) { M_1[i] = adjunct[i] * deter ; }
return GLU_SUCCESS ;
#else
#if NC == 2
// use the identity, should warn for singular matrices
const double complex INV_detM = 1.0 / ( det( M ) ) ;
M_1[ 0 ] = M[ 3 ] * INV_detM ;
M_1[ 1 ] = -M[ 1 ] * INV_detM ;
M_1[ 2 ] = -M[ 2 ] * INV_detM ;
M_1[ 3 ] = M[ 0 ] * INV_detM ;
return GLU_SUCCESS ;
#else
return gauss_jordan( M_1 , M ) ;
#endif
#endif
}
LinearEquation* run_gaussj(LinearEquation *leq) {
gauss_jordan(leq->A, leq->n, leq->b, leq->x);
return leq;
}
