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63 lines
1.8 KiB
C++
63 lines
1.8 KiB
C++
// This file is part of Eigen, a lightweight C++ template library
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// for linear algebra.
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//
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// Copyright (C) 2011 Gael Guennebaud <gael.guennebaud@inria.fr>
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//
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// This Source Code Form is subject to the terms of the Mozilla
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// Public License v. 2.0. If a copy of the MPL was not distributed
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// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
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#include "lapack_common.h"
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#include <Eigen/Eigenvalues>
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// computes eigen values and vectors of a general N-by-N matrix A
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EIGEN_LAPACK_FUNC(syev,(char *jobz, char *uplo, int* n, Scalar* a, int *lda, Scalar* w, Scalar* /*work*/, int* lwork, int *info))
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{
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// TODO exploit the work buffer
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bool query_size = *lwork==-1;
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*info = 0;
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if(*jobz!='N' && *jobz!='V') *info = -1;
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else if(UPLO(*uplo)==INVALID) *info = -2;
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else if(*n<0) *info = -3;
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else if(*lda<std::max(1,*n)) *info = -5;
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else if((!query_size) && *lwork<std::max(1,3**n-1)) *info = -8;
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if(*info!=0)
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{
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int e = -*info;
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return xerbla_(SCALAR_SUFFIX_UP"SYEV ", &e, 6);
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}
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if(query_size)
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{
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*lwork = 0;
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return 0;
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}
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if(*n==0)
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return 0;
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PlainMatrixType mat(*n,*n);
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if(UPLO(*uplo)==UP) mat = matrix(a,*n,*n,*lda).adjoint();
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else mat = matrix(a,*n,*n,*lda);
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bool computeVectors = *jobz=='V' || *jobz=='v';
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SelfAdjointEigenSolver<PlainMatrixType> eig(mat,computeVectors?ComputeEigenvectors:EigenvaluesOnly);
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if(eig.info()==NoConvergence)
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{
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make_vector(w,*n).setZero();
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if(computeVectors)
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matrix(a,*n,*n,*lda).setIdentity();
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//*info = 1;
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return 0;
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}
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make_vector(w,*n) = eig.eigenvalues();
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if(computeVectors)
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matrix(a,*n,*n,*lda) = eig.eigenvectors();
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return 0;
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}
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