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authorSiddhesh Wani2015-05-25 14:46:31 +0530
committerSiddhesh Wani2015-05-25 14:46:31 +0530
commit6a320264c2de3d6dd8cc1d1327b3c30df4c8cb26 (patch)
tree1b7bd89fdcfd01715713d8a15db471dc75a96bbf /2.3-1/src/c/matrixOperations/determ/ddeterma.c
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Original Version
Diffstat (limited to '2.3-1/src/c/matrixOperations/determ/ddeterma.c')
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diff --git a/2.3-1/src/c/matrixOperations/determ/ddeterma.c b/2.3-1/src/c/matrixOperations/determ/ddeterma.c
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+/*
+ * Scilab ( http://www.scilab.org/ ) - This file is part of Scilab
+ * Copyright (C) 2008 - INRIA - Arnaud TORSET
+ *
+ * This file must be used under the terms of the CeCILL.
+ * This source file is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at
+ * http://www.cecill.info/licences/Licence_CeCILL_V2-en.txt
+ *
+ */
+
+#include <stdlib.h>
+#ifndef WITHOUT_LAPACK
+#include "lapack.h"
+#endif
+#include "determ.h"
+#include "lapack.h"
+
+double ddeterma(double * in, int size){
+#ifndef WITHOUT_LAPACK
+ int i=0, info=0;
+ double out=0;
+ double *inCopy=NULL;
+ int* tmp=NULL;
+
+ /*Calculation of the determinant*/
+ switch (size){
+ case 2 : out = in[0]*in[3]-in[1]*in[2];
+ break;
+ case 3 : /*regle de Sarrus*/
+ out = in[0]*in[4]*in[8]+in[1]*in[5]*in[6]+in[2]*in[3]*in[7]
+ -in[0]*in[5]*in[7]-in[1]*in[3]*in[8]-in[2]*in[4]*in[6];
+ break;
+ default :
+
+ /*Copy the input matrix*/
+ inCopy=(double*)malloc((unsigned int)(size*size)*sizeof(double));
+ for (i=0;i<size*size;i++) inCopy[i]=in[i];
+
+ tmp=(int*)malloc((unsigned int)size*sizeof(int));
+ dgetrf_(&size, &size, inCopy, &size, tmp, &info);
+ out=1;
+ for (i=0;i<size;i++){
+ if (tmp[i]!=i+1) out=-out;
+ out=inCopy[i*(size+1)]*out;
+ }
+ free(tmp);
+ free(inCopy);
+ break;
+ }
+
+#else
+ int i=0, j=0, k=0;
+ double out=0, pivot=0;
+ double *inCopy=NULL;
+
+ /*Calculation of the determinant*/
+ switch (size){
+ case 2 : out = in[0]*in[3]-in[1]*in[2];
+ break;
+ case 3 : /*regle de Sarrus*/
+ out = in[0]*in[4]*in[8]+in[1]*in[5]*in[6]+in[2]*in[3]*in[7]
+ -in[0]*in[5]*in[7]-in[1]*in[3]*in[8]-in[2]*in[4]*in[6];
+ break;
+ default :
+
+ /*Copy the input matrix*/
+ inCopy=malloc((unsigned int)(size*size)*sizeof(double));
+ for (i=0;i<size*size;i++) inCopy[i]=in[i];
+
+ for (i=0;i<size;i++){
+ for (j=i+1;j<size;j++){
+ pivot = inCopy[i*size+j]/inCopy[i*size+i];
+ for (k=0;k<size-i;k++){
+ inCopy[i*size+j+k*size]-=pivot*inCopy[i*size+i+k*size];
+ }
+ }
+ }
+ out=1;
+ for (i=0;i<size;i++){
+ out *= inCopy[i*size+i];
+ }
+ free(inCopy);
+ break;
+
+ }
+#endif
+
+
+ return out;
+}