source: pacpussensors/trunk/Vislab/lib3dv-1.2.0/lib3dv/eigen/lapack/eigenvalues.cpp

Last change on this file was 136, checked in by ldecherf, 8 years ago

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1// This file is part of Eigen, a lightweight C++ template library
2// for linear algebra.
3//
4// Copyright (C) 2011 Gael Guennebaud <gael.guennebaud@inria.fr>
5//
6// This Source Code Form is subject to the terms of the Mozilla
7// Public License v. 2.0. If a copy of the MPL was not distributed
8// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
9
10#include "common.h"
11#include <Eigen/Eigenvalues>
12
13// computes an LU factorization of a general M-by-N matrix A using partial pivoting with row interchanges
14EIGEN_LAPACK_FUNC(syev,(char *jobz, char *uplo, int* n, Scalar* a, int *lda, Scalar* w, Scalar* /*work*/, int* lwork, int *info))
15{
16 // TODO exploit the work buffer
17 bool query_size = *lwork==-1;
18
19 *info = 0;
20 if(*jobz!='N' && *jobz!='V') *info = -1;
21 else if(UPLO(*uplo)==INVALID) *info = -2;
22 else if(*n<0) *info = -3;
23 else if(*lda<std::max(1,*n)) *info = -5;
24 else if((!query_size) && *lwork<std::max(1,3**n-1)) *info = -8;
25
26// if(*info==0)
27// {
28// int nb = ILAENV( 1, 'SSYTRD', UPLO, N, -1, -1, -1 )
29// LWKOPT = MAX( 1, ( NB+2 )*N )
30// WORK( 1 ) = LWKOPT
31// *
32// IF( LWORK.LT.MAX( 1, 3*N-1 ) .AND. .NOT.LQUERY )
33// $ INFO = -8
34// END IF
35// *
36// IF( INFO.NE.0 ) THEN
37// CALL XERBLA( 'SSYEV ', -INFO )
38// RETURN
39// ELSE IF( LQUERY ) THEN
40// RETURN
41// END IF
42
43 if(*info!=0)
44 {
45 int e = -*info;
46 return xerbla_(SCALAR_SUFFIX_UP"SYEV ", &e, 6);
47 }
48
49 if(query_size)
50 {
51 *lwork = 0;
52 return 0;
53 }
54
55 if(*n==0)
56 return 0;
57
58 PlainMatrixType mat(*n,*n);
59 if(UPLO(*uplo)==UP) mat = matrix(a,*n,*n,*lda).adjoint();
60 else mat = matrix(a,*n,*n,*lda);
61
62 bool computeVectors = *jobz=='V' || *jobz=='v';
63 SelfAdjointEigenSolver<PlainMatrixType> eig(mat,computeVectors?ComputeEigenvectors:EigenvaluesOnly);
64
65 if(eig.info()==NoConvergence)
66 {
67 vector(w,*n).setZero();
68 if(computeVectors)
69 matrix(a,*n,*n,*lda).setIdentity();
70 //*info = 1;
71 return 0;
72 }
73
74 vector(w,*n) = eig.eigenvalues();
75 if(computeVectors)
76 matrix(a,*n,*n,*lda) = eig.eigenvectors();
77
78 return 0;
79}
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