/*----------------------------------------------------------------------------------------- * Copyright (C) 2016 For the list of authors, see file AUTHORS. * * This file is part of IFOS. * * IFOS is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, version 2.0 of the License only. * * IFOS is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with IFOS. See file COPYING and/or . -----------------------------------------------------------------------------------------*/ /* *------------------------------------------------------------------------ * * Solve linear equation systems * *------------------------------------------------------------------------ */ #include "fd.h" void solvelin(float **AA, float *bb, float *x, int e, int method) { /* local variables */ int k, m, n, rows, columns; float a, c, **A, *b; rows = e; columns = e; A = matrix(1,rows,1,columns); b = vector(1,rows); /* temporary variables */ for (k=1;k<=rows;k++) { for (n=1;n<=columns;n++) A[k][n] = AA[k][n]; b[k] = bb[k]; } switch (method) { case 1: /* Gauß algorithm */ { for (k=1;k<=rows-1;k++) for (n=k;n<=rows-1;n++) { a = A[n+1][k]/A[k][k]; for (m=1;m<=columns;m++) A[n+1][m] = A[n+1][m] - a*A[k][m]; b[n+1] = b[n+1] - a*b[k]; } for (k=rows;k>=1;k--) { c = b[k]; for (m=columns;m>=k+1;m--) c = c - A[k][m]*x[m]; x[k] = c/A[k][k]; } break; } /* END of case Gauß */ } /* END of switch (method) */ free_matrix(A,1,rows,1,columns); free_vector(b,1,rows); return; }