1 files changed, 46 insertions, 0 deletions
diff --git a/src/c/linearAlgebra/rcond/drconda.c b/src/c/linearAlgebra/rcond/drconda.c
new file mode 100644
index 0000000..2082e9d
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+++ b/src/c/linearAlgebra/rcond/drconda.c
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+/* Copyright (C) 2017 - IIT Bombay - FOSSEE
+
+ 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
+ Author: Siddhesh Wani
+ Organization: FOSSEE, IIT Bombay
+ Email: toolbox@scilab.in
+ */
+
+/*Funtion to find inverse condition number of square matrix*/
+
+#include "lapack.h"
+#include "stdlib.h"
+#include "string.h"
+
+double drconda(double* in1, int rows)
+{
+	double *buf, *IPIV, *LDWORK, *LIWORK;
+	int INFO;
+	char one = '1';
+	double ANORM;
+	double RCOND = 1;
+
+	buf   = (double*) malloc((double) rows*rows*sizeof(double));
+	IPIV   = (double*) malloc((double) rows*sizeof(double));
+	LIWORK = (double*) malloc((double) rows*sizeof(double));
+	LDWORK = (double*) malloc((double) 4*rows*sizeof(double));
+
+	/*Copy input in temp buf, as lapack modifies input*/
+	memcpy(buf,in1,rows*rows*sizeof(double));
+
+	ANORM = dlange_(&one,&rows,&rows,buf,&rows,LDWORK); 
+
+	dgetrf_(&rows,&rows,buf,&rows,IPIV,&INFO);
+	
+	if(INFO == 0)
+	{
+		dgecon_(&one,&rows,buf,&rows,&ANORM,&RCOND,LDWORK,LIWORK,&INFO);
+	}
+
+	return RCOND;
+
+}
+\ No newline at end of file