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      1 // This file is part of Eigen, a lightweight C++ template library
      2 // for linear algebra.
      3 //
      4 // Copyright (C) 2014 Gael Guennebaud <gael.guennebaud (at) 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 "lapack_common.h"
     11 #include <Eigen/SVD>
     12 
     13 // computes the singular values/vectors a general M-by-N matrix A using divide-and-conquer
     14 EIGEN_LAPACK_FUNC(gesdd,(char *jobz, int *m, int* n, Scalar* a, int *lda, RealScalar *s, Scalar *u, int *ldu, Scalar *vt, int *ldvt, Scalar* /*work*/, int* lwork,
     15                          EIGEN_LAPACK_ARG_IF_COMPLEX(RealScalar */*rwork*/) int * /*iwork*/, int *info))
     16 {
     17   // TODO exploit the work buffer
     18   bool query_size = *lwork==-1;
     19   int diag_size = (std::min)(*m,*n);
     20 
     21   *info = 0;
     22         if(*jobz!='A' && *jobz!='S' && *jobz!='O' && *jobz!='N')  *info = -1;
     23   else  if(*m<0)                                                  *info = -2;
     24   else  if(*n<0)                                                  *info = -3;
     25   else  if(*lda<std::max(1,*m))                                   *info = -5;
     26   else  if(*lda<std::max(1,*m))                                   *info = -8;
     27   else  if(*ldu <1 || (*jobz=='A' && *ldu <*m)
     28                    || (*jobz=='O' && *m<*n && *ldu<*m))           *info = -8;
     29   else  if(*ldvt<1 || (*jobz=='A' && *ldvt<*n)
     30                    || (*jobz=='S' && *ldvt<diag_size)
     31                    || (*jobz=='O' && *m>=*n && *ldvt<*n))         *info = -10;
     32 
     33   if(*info!=0)
     34   {
     35     int e = -*info;
     36     return xerbla_(SCALAR_SUFFIX_UP"GESDD ", &e, 6);
     37   }
     38 
     39   if(query_size)
     40   {
     41     *lwork = 0;
     42     return 0;
     43   }
     44 
     45   if(*n==0 || *m==0)
     46     return 0;
     47 
     48   PlainMatrixType mat(*m,*n);
     49   mat = matrix(a,*m,*n,*lda);
     50 
     51   int option = *jobz=='A' ? ComputeFullU|ComputeFullV
     52              : *jobz=='S' ? ComputeThinU|ComputeThinV
     53              : *jobz=='O' ? ComputeThinU|ComputeThinV
     54              : 0;
     55 
     56   BDCSVD<PlainMatrixType> svd(mat,option);
     57 
     58   make_vector(s,diag_size) = svd.singularValues().head(diag_size);
     59 
     60   if(*jobz=='A')
     61   {
     62     matrix(u,*m,*m,*ldu)   = svd.matrixU();
     63     matrix(vt,*n,*n,*ldvt) = svd.matrixV().adjoint();
     64   }
     65   else if(*jobz=='S')
     66   {
     67     matrix(u,*m,diag_size,*ldu)   = svd.matrixU();
     68     matrix(vt,diag_size,*n,*ldvt) = svd.matrixV().adjoint();
     69   }
     70   else if(*jobz=='O' && *m>=*n)
     71   {
     72     matrix(a,*m,*n,*lda)   = svd.matrixU();
     73     matrix(vt,*n,*n,*ldvt) = svd.matrixV().adjoint();
     74   }
     75   else if(*jobz=='O')
     76   {
     77     matrix(u,*m,*m,*ldu)        = svd.matrixU();
     78     matrix(a,diag_size,*n,*lda) = svd.matrixV().adjoint();
     79   }
     80 
     81   return 0;
     82 }
     83 
     84 // computes the singular values/vectors a general M-by-N matrix A using two sided jacobi algorithm
     85 EIGEN_LAPACK_FUNC(gesvd,(char *jobu, char *jobv, int *m, int* n, Scalar* a, int *lda, RealScalar *s, Scalar *u, int *ldu, Scalar *vt, int *ldvt, Scalar* /*work*/, int* lwork,
     86                          EIGEN_LAPACK_ARG_IF_COMPLEX(RealScalar */*rwork*/) int *info))
     87 {
     88   // TODO exploit the work buffer
     89   bool query_size = *lwork==-1;
     90   int diag_size = (std::min)(*m,*n);
     91 
     92   *info = 0;
     93         if( *jobu!='A' && *jobu!='S' && *jobu!='O' && *jobu!='N') *info = -1;
     94   else  if((*jobv!='A' && *jobv!='S' && *jobv!='O' && *jobv!='N')
     95            || (*jobu=='O' && *jobv=='O'))                         *info = -2;
     96   else  if(*m<0)                                                  *info = -3;
     97   else  if(*n<0)                                                  *info = -4;
     98   else  if(*lda<std::max(1,*m))                                   *info = -6;
     99   else  if(*ldu <1 || ((*jobu=='A' || *jobu=='S') && *ldu<*m))    *info = -9;
    100   else  if(*ldvt<1 || (*jobv=='A' && *ldvt<*n)
    101                    || (*jobv=='S' && *ldvt<diag_size))            *info = -11;
    102 
    103   if(*info!=0)
    104   {
    105     int e = -*info;
    106     return xerbla_(SCALAR_SUFFIX_UP"GESVD ", &e, 6);
    107   }
    108 
    109   if(query_size)
    110   {
    111     *lwork = 0;
    112     return 0;
    113   }
    114 
    115   if(*n==0 || *m==0)
    116     return 0;
    117 
    118   PlainMatrixType mat(*m,*n);
    119   mat = matrix(a,*m,*n,*lda);
    120 
    121   int option = (*jobu=='A' ? ComputeFullU : *jobu=='S' || *jobu=='O' ? ComputeThinU : 0)
    122              | (*jobv=='A' ? ComputeFullV : *jobv=='S' || *jobv=='O' ? ComputeThinV : 0);
    123 
    124   JacobiSVD<PlainMatrixType> svd(mat,option);
    125 
    126   make_vector(s,diag_size) = svd.singularValues().head(diag_size);
    127   {
    128         if(*jobu=='A') matrix(u,*m,*m,*ldu)           = svd.matrixU();
    129   else  if(*jobu=='S') matrix(u,*m,diag_size,*ldu)    = svd.matrixU();
    130   else  if(*jobu=='O') matrix(a,*m,diag_size,*lda)    = svd.matrixU();
    131   }
    132   {
    133         if(*jobv=='A') matrix(vt,*n,*n,*ldvt)         = svd.matrixV().adjoint();
    134   else  if(*jobv=='S') matrix(vt,diag_size,*n,*ldvt)  = svd.matrixV().adjoint();
    135   else  if(*jobv=='O') matrix(a,diag_size,*n,*lda)    = svd.matrixV().adjoint();
    136   }
    137   return 0;
    138 }
    139