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Updated: June 2017
 
 

dlalsa (3p)

Name

dlalsa - compute the SVD of the coefficient matrix in compact form. Used by dgelsd

Synopsis

SUBROUTINE DLALSA(ICOMPQ, SMLSIZ, N, NRHS, B, LDB, BX,  LDBX,  U,  LDU,
VT,  K,  DIFL,  DIFR, Z, POLES, GIVPTR, GIVCOL, LDGCOL, PERM,
GIVNUM, C, S, WORK, IWORK, INFO)


INTEGER ICOMPQ, INFO, LDB, LDBX, LDGCOL, LDU, N, NRHS, SMLSIZ

INTEGER GIVCOL(LDGCOL,*), GIVPTR(*), IWORK(*), K(*), PERM(LDGCOL,*)

DOUBLE PRECISION B(LDB,*), BX(LDBX,*), C(*), DIFL(LDU,*),  DIFR(LDU,*),
GIVNUM(LDU,*),   POLES(LDU,*),   S(*),  U(LDU,*),  VT(LDU,*),
WORK(*), Z(LDU,*)


SUBROUTINE DLALSA_64(ICOMPQ, SMLSIZ, N, NRHS, B, LDB, BX, LDBX, U, LDU,
VT,  K,  DIFL,  DIFR, Z, POLES, GIVPTR, GIVCOL, LDGCOL, PERM,
GIVNUM, C, S, WORK, IWORK, INFO)


INTEGER*8 ICOMPQ, INFO, LDB, LDBX, LDGCOL, LDU, N, NRHS, SMLSIZ

INTEGER*8 GIVCOL(LDGCOL,*), GIVPTR(*), IWORK(*), K(*), PERM(LDGCOL,*)

DOUBLE PRECISION B(LDB,*), BX(LDBX,*), C(*), DIFL(LDU,*),  DIFR(LDU,*),
GIVNUM(LDU,*),   POLES(LDU,*),   S(*),  U(LDU,*),  VT(LDU,*),
WORK(*), Z(LDU,*)


F95 INTERFACE
SUBROUTINE LALSA(ICOMPQ, SMLSIZ, N, NRHS, B, LDB, BX, LDBX, U, LDU, VT,
K,  DIFL,  DIFR,  Z,  POLES,  GIVPTR,  GIVCOL,  LDGCOL, PERM,
GIVNUM, C, S, WORK, IWORK, INFO)


REAL(8), DIMENSION(:,:) :: B, BX, U, VT, DIFL, DIFR, Z, POLES, GIVNUM

INTEGER :: ICOMPQ, SMLSIZ, N, NRHS, LDB, LDBX, LDU, LDGCOL, INFO

INTEGER, DIMENSION(:) :: K, GIVPTR, IWORK

REAL(8), DIMENSION(:) :: C, S, WORK

INTEGER, DIMENSION(:,:) :: GIVCOL, PERM


SUBROUTINE LALSA_64(ICOMPQ, SMLSIZ, N, NRHS, B, LDB, BX, LDBX, U,  LDU,
VT,  K,  DIFL,  DIFR, Z, POLES, GIVPTR, GIVCOL, LDGCOL, PERM,
GIVNUM, C, S, WORK, IWORK, INFO)


REAL(8), DIMENSION(:,:) :: B, BX, U, VT, DIFL, DIFR, Z, POLES, GIVNUM

INTEGER(8) :: ICOMPQ, SMLSIZ, N, NRHS, LDB, LDBX, LDU, LDGCOL, INFO

INTEGER(8), DIMENSION(:) :: K, GIVPTR, IWORK

REAL(8), DIMENSION(:) :: C, S, WORK

INTEGER(8), DIMENSION(:,:) :: GIVCOL, PERM



C INTERFACE
#include <sunperf.h>

void dlalsa (int icompq, int smlsiz, int n, int nrhs,  double  *b,  int
ldb,  double  *bx,  int ldbx, double *u, int ldu, double *vt,
int *k, double *difl, double *difr, double *z, double *poles,
int  *givptr,  int  *givcol,  int  ldgcol,  int *perm, double
*givnum, double *c, double *s, int *info);


void dlalsa_64 (long icompq, long smlsiz, long n, long nrhs, double *b,
long  ldb, double *bx, long ldbx, double *u, long ldu, double
*vt, long *k, double *difl, double *difr, double  *z,  double
*poles,  long *givptr, long *givcol, long ldgcol, long *perm,
double *givnum, double *c, double *s, long *info);

Description

Oracle Solaris Studio Performance Library                           dlalsa(3P)



NAME
       dlalsa  -  compute  the  SVD of the coefficient matrix in compact form.
       Used by dgelsd


SYNOPSIS
       SUBROUTINE DLALSA(ICOMPQ, SMLSIZ, N, NRHS, B, LDB, BX,  LDBX,  U,  LDU,
                 VT,  K,  DIFL,  DIFR, Z, POLES, GIVPTR, GIVCOL, LDGCOL, PERM,
                 GIVNUM, C, S, WORK, IWORK, INFO)


       INTEGER ICOMPQ, INFO, LDB, LDBX, LDGCOL, LDU, N, NRHS, SMLSIZ

       INTEGER GIVCOL(LDGCOL,*), GIVPTR(*), IWORK(*), K(*), PERM(LDGCOL,*)

       DOUBLE PRECISION B(LDB,*), BX(LDBX,*), C(*), DIFL(LDU,*),  DIFR(LDU,*),
                 GIVNUM(LDU,*),   POLES(LDU,*),   S(*),  U(LDU,*),  VT(LDU,*),
                 WORK(*), Z(LDU,*)


       SUBROUTINE DLALSA_64(ICOMPQ, SMLSIZ, N, NRHS, B, LDB, BX, LDBX, U, LDU,
                 VT,  K,  DIFL,  DIFR, Z, POLES, GIVPTR, GIVCOL, LDGCOL, PERM,
                 GIVNUM, C, S, WORK, IWORK, INFO)


       INTEGER*8 ICOMPQ, INFO, LDB, LDBX, LDGCOL, LDU, N, NRHS, SMLSIZ

       INTEGER*8 GIVCOL(LDGCOL,*), GIVPTR(*), IWORK(*), K(*), PERM(LDGCOL,*)

       DOUBLE PRECISION B(LDB,*), BX(LDBX,*), C(*), DIFL(LDU,*),  DIFR(LDU,*),
                 GIVNUM(LDU,*),   POLES(LDU,*),   S(*),  U(LDU,*),  VT(LDU,*),
                 WORK(*), Z(LDU,*)


   F95 INTERFACE
       SUBROUTINE LALSA(ICOMPQ, SMLSIZ, N, NRHS, B, LDB, BX, LDBX, U, LDU, VT,
                 K,  DIFL,  DIFR,  Z,  POLES,  GIVPTR,  GIVCOL,  LDGCOL, PERM,
                 GIVNUM, C, S, WORK, IWORK, INFO)


       REAL(8), DIMENSION(:,:) :: B, BX, U, VT, DIFL, DIFR, Z, POLES, GIVNUM

       INTEGER :: ICOMPQ, SMLSIZ, N, NRHS, LDB, LDBX, LDU, LDGCOL, INFO

       INTEGER, DIMENSION(:) :: K, GIVPTR, IWORK

       REAL(8), DIMENSION(:) :: C, S, WORK

       INTEGER, DIMENSION(:,:) :: GIVCOL, PERM


       SUBROUTINE LALSA_64(ICOMPQ, SMLSIZ, N, NRHS, B, LDB, BX, LDBX, U,  LDU,
                 VT,  K,  DIFL,  DIFR, Z, POLES, GIVPTR, GIVCOL, LDGCOL, PERM,
                 GIVNUM, C, S, WORK, IWORK, INFO)


       REAL(8), DIMENSION(:,:) :: B, BX, U, VT, DIFL, DIFR, Z, POLES, GIVNUM

       INTEGER(8) :: ICOMPQ, SMLSIZ, N, NRHS, LDB, LDBX, LDU, LDGCOL, INFO

       INTEGER(8), DIMENSION(:) :: K, GIVPTR, IWORK

       REAL(8), DIMENSION(:) :: C, S, WORK

       INTEGER(8), DIMENSION(:,:) :: GIVCOL, PERM



   C INTERFACE
       #include <sunperf.h>

       void dlalsa (int icompq, int smlsiz, int n, int nrhs,  double  *b,  int
                 ldb,  double  *bx,  int ldbx, double *u, int ldu, double *vt,
                 int *k, double *difl, double *difr, double *z, double *poles,
                 int  *givptr,  int  *givcol,  int  ldgcol,  int *perm, double
                 *givnum, double *c, double *s, int *info);


       void dlalsa_64 (long icompq, long smlsiz, long n, long nrhs, double *b,
                 long  ldb, double *bx, long ldbx, double *u, long ldu, double
                 *vt, long *k, double *difl, double *difr, double  *z,  double
                 *poles,  long *givptr, long *givcol, long ldgcol, long *perm,
                 double *givnum, double *c, double *s, long *info);


PURPOSE
       dlalsa is an itermediate step in solving the least squares  problem  by
       computing the SVD of the coefficient matrix in compact form (The singu-
       lar vectors are computed as products of simple orthorgonal  matrices.).

       If  ICOMPQ  = 0, DLALSA applies the inverse of the left singular vector
       matrix of an upper bidiagonal matrix to the right  hand  side;  and  if
       ICOMPQ  =  1,  DLALSA  applies  the right singular vector matrix to the
       right hand side. The singular vector matrices were generated in compact
       form by DLALSA.


ARGUMENTS
       ICOMPQ (input)
                 ICOMPQ is INTEGER
                 Specifies  whether  the  left  or  the  right singular vector
                 matrix is involved.
                 = 0: Left singular vector matrix,
                 = 1: Right singular vector matrix.


       SMLSIZ (input)
                 SMLSIZ is INTEGER
                 The maximum size of the subproblems at the bottom of the com-
                 putation tree.


       N (input)
                 N is INTEGER
                 The row and column dimensions of the upper bidiagonal matrix.


       NRHS (input)
                 NRHS is INTEGER
                 The number of columns of B and BX. NRHS must be at least 1.


       B (input/output)
                 B is DOUBLE PRECISION array, dimension (LDB, NRHS)
                 On input, B contains  the  right  hand  sides  of  the  least
                 squares problem in rows 1 through M.
                 On output, B contains the solution X in rows 1 through N.


       LDB (input)
                 LDB is INTEGER
                 The leading dimension of B in the calling subprogram.
                 LDB must be at least max(1,MAX(M,N)).


       BX (output)
                 BX is DOUBLE PRECISION array, dimension (LDBX,NRHS)
                 On  exit,  the  result of applying the left or right singular
                 vector matrix to B.


       LDBX (input)
                 LDBX is INTEGER
                 The leading dimension of BX.


       U (input)
                 U is DOUBLE PRECISION array, dimension (LDU, SMLSIZ)
                 On entry, U contains the left singular vector matrices of all
                 subproblems at the bottom level.


       LDU (input)
                 LDU is INTEGER, LDU = > N.
                 The  leading  dimension  of  arrays U, VT, DIFL, DIFR, POLES,
                 GIVNUM, and Z.


       VT (input)
                 VT is DOUBLE PRECISION array, dimension (LDU, SMLSIZ+1)
                 On entry, VT**T contains the right singular  vector  matrices
                 of all subproblems at the bottom level.


       K (input)
                 K is INTEGER array, dimension (N)


       DIFL (input)
                 DIFL is DOUBLE PRECISION array, dimension (LDU, NLVL)
                 where NLVL = INT(log_2 (N/(SMLSIZ+1))) + 1.


       DIFR (input)
                 DIFR is DOUBLE PRECISION array, dimension (LDU, 2*NLVL)
                 On  entry,  DIFL(*,  I)  and  DIFR(*, 2*I-1) record distances
                 between singular values on the I-th level and singular values
                 on  the (I-1)-th level, and DIFR(*, 2*I) record the normaliz-
                 ing factors of the right singular vectors  matrices  of  sub-
                 problems on I-th level.


       Z (input)
                 Z is DOUBLE PRECISION array, dimension (LDU, NLVL)
                 On  entry,  Z(1, I) contains the components of the deflation-
                 adjusted updating row vector  for  subproblems  on  the  I-th
                 level.


       POLES (input)
                 POLES is DOUBLE PRECISION array, dimension (LDU, 2*NLVL)
                 On entry, POLES(*, 2*I-1 : 2*I) contains the new and old sin-
                 gular values involved in the secular equations  on  the  I-th
                 level.


       GIVPTR (input)
                 GIVPTR is INTEGER array, dimension (N)
                 On  entry,  GIVPTR(I)  records the number of Givens rotations
                 performed on the I-th problem on the computation tree.


       GIVCOL (input)
                 GIVCOL is INTEGER array, dimension (LDGCOL, 2*NLVL).
                 On entry, for each I, GIVCOL(*,  2*I-1  :  2*I)  records  the
                 locations  of Givens rotations performed on the I-th level on
                 the computation tree.


       LDGCOL (input)
                 LDGCOL is INTEGER, LDGCOL = > N.
                 The leading dimension of arrays GIVCOL and PERM.


       PERM (input)
                 PERM is INTEGER array, dimension (LDGCOL, NLVL)
                 On entry, PERM(*, I) records permutations done  on  the  I-th
                 level of the computation tree.


       GIVNUM (input)
                 GIVNUM is DOUBLE PRECISION array, dimension (LDU, 2*NLVL)
                 On entry, GIVNUM(*, 2*I-1 : 2*I) records the C- and S- values
                 of Givens rotations performed on the I-th level on the compu-
                 tation tree.


       C (input)
                 C is DOUBLE PRECISION array, dimension (N)
                 On entry, if the I-th subproblem is not square, C(I) contains
                 the C-value of a Givens rotation related to  the  right  null
                 space of the I-th subproblem.


       S (input)
                 S is DOUBLE PRECISION array, dimension (N)
                 On entry, if the I-th subproblem is not square, S(I) contains
                 the S-value of a Givens rotation related to  the  right  null
                 space of the I-th subproblem.


       WORK (output)
                 WORK is DOUBLE PRECISION array
                 The dimension must be at least N.


       IWORK (output)
                 IWORK is INTEGER array
                 The dimension must be at least 3*N.


       INFO (output)
                 INFO is INTEGER
                 = 0:  successful exit,
                 < 0:  if INFO = -i, the i-th argument had an illegal value.




                                  7 Nov 2015                        dlalsa(3P)