From 362bd2337910fec57d854ebb179772efe552f929 Mon Sep 17 00:00:00 2001
From: Sandeep Gupta
Date: Mon, 19 Jun 2017 17:02:45 +0530
Subject: 19-June-2017

---
 src/c/linearAlgebra/spec2/zspec2a.c | 96 +++++++++++++++++++++++++++++++++++++
 1 file changed, 96 insertions(+)
 create mode 100644 src/c/linearAlgebra/spec2/zspec2a.c

(limited to 'src/c/linearAlgebra/spec2/zspec2a.c')

diff --git a/src/c/linearAlgebra/spec2/zspec2a.c b/src/c/linearAlgebra/spec2/zspec2a.c
new file mode 100644
index 0000000..e33ed89
--- /dev/null
+++ b/src/c/linearAlgebra/spec2/zspec2a.c
@@ -0,0 +1,96 @@
+/*
+ *  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>
+#include "spec.h"
+#include "lapack.h"
+#include "zeros.h"
+#include "stdio.h"
+#include "conj.h"
+
+void zspec2a(doubleComplex* in, int rows,doubleComplex* eigenvalues, doubleComplex* eigenvectors){
+	int i = 0, j = 0;
+	int hermitian = 0;
+	int INFO = 0;
+	int iWorkSize = 0;
+	doubleComplex* pdblWork;
+	doubleComplex* pdblLeftvectors;
+	doubleComplex* pdblRightvectors;
+	doubleComplex* pdblRWork;
+	double* pdblRWork2;
+	double* outReal;
+	double* outImag;
+	doubleComplex* inCopy;
+	
+	inCopy = (doubleComplex*)malloc((unsigned int)(rows*rows) * sizeof(doubleComplex));
+	outReal = (double*)malloc((unsigned int)rows * sizeof(double));
+	outImag = (double*)malloc((unsigned int)rows * sizeof(double));
+	pdblLeftvectors=NULL;
+	pdblRightvectors=NULL;
+	
+	iWorkSize = 2*rows;
+	pdblWork = (doubleComplex*)malloc((unsigned int)iWorkSize * sizeof(doubleComplex));
+	pdblRWork = NULL;	
+	pdblRWork2 = NULL;
+	
+	for(i=0;i<rows*rows;i++) {
+		inCopy[i]=DoubleComplex(zreals(in[i]),zimags(in[i]));
+		eigenvectors[i]=DoubleComplex(zreals(in[i]),zimags(in[i]));
+	}	
+	zzerosa(eigenvalues,1,rows*rows);
+	
+	
+	/* look if the matrix is symmetric */
+	for (i=0;i<rows;i++){
+		for (j=0;j<rows;j++) 
+			if ( (zreals(in[i*rows+j])!=zreals(zconjs(in[i+j*rows]))) ||
+			     (zimags(in[i*rows+j])!=zimags(zconjs(in[i+j*rows])))  )
+			     break;
+		if (j!=rows) break;
+	}
+		
+	
+	/* the matrix is symmetric if the 2 loops goes to end i.e
+		i==rows and j==rows */
+	if ((i==rows)&&(j==rows)) hermitian=1;
+	
+	
+	/* apply lapack function according to symmetry */
+	if(hermitian){
+		pdblRWork2 = (double*)malloc((unsigned int)(3*rows) * sizeof(double));
+		C2F(zheev)( "V", "U", &rows, eigenvectors, &rows, outReal, pdblWork, &iWorkSize, pdblRWork2, &INFO );
+		dzerosa(outImag,1,rows);
+		for (i=0;i<rows;i++) eigenvalues[i+i*rows]=DoubleComplex(outReal[i],outImag[i]);
+	}
+	else {
+		pdblRWork = (doubleComplex*)malloc((unsigned int)(3*rows) * sizeof(doubleComplex));	
+		C2F(zgeev)( "N", "V", &rows, inCopy, &rows, eigenvalues, 
+		pdblLeftvectors, &rows, eigenvectors, &rows, pdblWork, &iWorkSize,
+		pdblRWork, &INFO );
+		for (i=1;i<rows;i++) {
+			eigenvalues[i+i*rows]=DoubleComplex(zreals(eigenvalues[i]),zimags(eigenvalues[i]));
+			eigenvalues[i]=DoubleComplex(0,0);
+		}
+	}
+	
+	
+
+
+	free(inCopy);
+	free(outReal);
+	free(outImag);
+	free(pdblWork);
+	free(pdblRWork);
+	free(pdblRWork2);
+	free(pdblLeftvectors);
+	free(pdblRightvectors);
+}
-- 
cgit