00001 /* 00002 This file belongs to Aeneas. Aeneas is a GNU package released under GPL 3 license. 00003 This code is a simulator for Submicron 3D Semiconductor Devices. 00004 It implements the Monte Carlo transport in 3D tetrahedra meshes 00005 for the simulation of the semiclassical Boltzmann equation for both electrons. 00006 It also includes all the relevant quantum effects for nanodevices. 00007 00008 Copyright (C) 2007 Jean Michel Sellier <sellier@dmi.unict.it> 00009 00010 This program is free software; you can redistribute it and/or modify 00011 it under the terms of the GNU General Public License as published by 00012 the Free Software Foundation; either version 3, or (at your option) 00013 any later version. 00014 00015 This program is distributed in the hope that it will be useful, 00016 but WITHOUT ANY WARRANTY; without even the implied warranty of 00017 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00018 GNU General Public License for more details. 00019 00020 You should have received a copy of the GNU General Public License 00021 along with this program. If not, see <http://www.gnu.org/licenses/>. 00022 */ 00023 00024 // Created on : 08 june 2007, Siracusa, Jean Michel Sellier 00025 // Last modified : 08 june 2007, Siracusa, Jean Michel Sellier 00026 00027 // solves the set of n linear equations A.x = B. Here a[1..n][1..n] is input, 00028 // not as the matrix A but rather as its LU decomposition, determined by the 00029 // routine ludcmp. indx[1..n] is input as the permutation vector returned by 00030 // ludcmp. b[1..n] is input as the right-hand side vector B, and returns with 00031 // the solution vector X. a, n and indx are not modified by this routine and can 00032 // be left in place for successive calls with different right-hand sides b. 00033 // This routine takes into account the possibility that b will begin with many 00034 // zero elements, so it is efficient for use in matrix inversion. 00035 00036 { 00037 int i,ii=0,ip,j; 00038 double sum; 00039 00040 for(i=1;i<=n;i++){ 00041 ip=indx[i]; 00042 sum=b[ip]; 00043 b[ip]=b[i]; 00044 if(ii) for(j=ii;j<=i-1;j++) sum-=a[i][j]*b[j]; 00045 else if(sum) ii=i; 00046 b[i]=sum; 00047 } 00048 for(i=n;i>=1;i--){ 00049 sum=b[i]; 00050 for(j=i+1;j<=n;j++) sum-=a[i][j]*b[j]; 00051 b[i]=sum/a[i][i]; 00052 } 00053 }