dormtr (3p)

Name

dormtr - N matrix C with Q*C or Q**T*C or C*Q**T or C*Q.

Synopsis

SUBROUTINE DORMTR(SIDE, UPLO, TRANS, M, N, A, LDA, TAU, C, LDC, WORK,
LWORK, INFO)

CHARACTER*1 SIDE, UPLO, TRANS
INTEGER M, N, LDA, LDC, LWORK, INFO
DOUBLE PRECISION A(LDA,*), TAU(*), C(LDC,*), WORK(*)

SUBROUTINE DORMTR_64(SIDE, UPLO, TRANS, M, N, A, LDA, TAU, C, LDC,
WORK, LWORK, INFO)

CHARACTER*1 SIDE, UPLO, TRANS
INTEGER*8 M, N, LDA, LDC, LWORK, INFO
DOUBLE PRECISION A(LDA,*), TAU(*), C(LDC,*), WORK(*)




F95 INTERFACE
SUBROUTINE ORMTR(SIDE, UPLO, TRANS, M, N, A, LDA, TAU, C,
LDC, WORK, LWORK, INFO)

CHARACTER(LEN=1) :: SIDE, UPLO, TRANS
INTEGER :: M, N, LDA, LDC, LWORK, INFO
REAL(8), DIMENSION(:) :: TAU, WORK
REAL(8), DIMENSION(:,:) :: A, C

SUBROUTINE ORMTR_64(SIDE, UPLO, TRANS, M, N, A, LDA, TAU, C,
LDC, WORK, LWORK, INFO)

CHARACTER(LEN=1) :: SIDE, UPLO, TRANS
INTEGER(8) :: M, N, LDA, LDC, LWORK, INFO
REAL(8), DIMENSION(:) :: TAU, WORK
REAL(8), DIMENSION(:,:) :: A, C




C INTERFACE
#include <sunperf.h>

void dormtr(char side, char uplo, char trans, int m, int n, double  *a,
int lda, double *tau, double *c, int ldc, int *info);

void dormtr_64(char side, char uplo, char trans, long m, long n, double
*a, long lda, double *tau, double *c, long ldc, long *info);

Description

Oracle Solaris Studio Performance Library                           dormtr(3P)



NAME
       dormtr  - overwrite the general real M-by-N matrix C with Q*C or Q**T*C
       or C*Q**T or C*Q.


SYNOPSIS
       SUBROUTINE DORMTR(SIDE, UPLO, TRANS, M, N, A, LDA, TAU, C, LDC, WORK,
             LWORK, INFO)

       CHARACTER*1 SIDE, UPLO, TRANS
       INTEGER M, N, LDA, LDC, LWORK, INFO
       DOUBLE PRECISION A(LDA,*), TAU(*), C(LDC,*), WORK(*)

       SUBROUTINE DORMTR_64(SIDE, UPLO, TRANS, M, N, A, LDA, TAU, C, LDC,
             WORK, LWORK, INFO)

       CHARACTER*1 SIDE, UPLO, TRANS
       INTEGER*8 M, N, LDA, LDC, LWORK, INFO
       DOUBLE PRECISION A(LDA,*), TAU(*), C(LDC,*), WORK(*)




   F95 INTERFACE
       SUBROUTINE ORMTR(SIDE, UPLO, TRANS, M, N, A, LDA, TAU, C,
              LDC, WORK, LWORK, INFO)

       CHARACTER(LEN=1) :: SIDE, UPLO, TRANS
       INTEGER :: M, N, LDA, LDC, LWORK, INFO
       REAL(8), DIMENSION(:) :: TAU, WORK
       REAL(8), DIMENSION(:,:) :: A, C

       SUBROUTINE ORMTR_64(SIDE, UPLO, TRANS, M, N, A, LDA, TAU, C,
              LDC, WORK, LWORK, INFO)

       CHARACTER(LEN=1) :: SIDE, UPLO, TRANS
       INTEGER(8) :: M, N, LDA, LDC, LWORK, INFO
       REAL(8), DIMENSION(:) :: TAU, WORK
       REAL(8), DIMENSION(:,:) :: A, C




   C INTERFACE
       #include <sunperf.h>

       void dormtr(char side, char uplo, char trans, int m, int n, double  *a,
                 int lda, double *tau, double *c, int ldc, int *info);

       void dormtr_64(char side, char uplo, char trans, long m, long n, double
                 *a, long lda, double *tau, double *c, long ldc, long *info);



PURPOSE
       dormtr overwrites the general real M-by-N matrix C with

                       SIDE = 'L'     SIDE = 'R'
       TRANS = 'N':      Q * C          C * Q
       TRANS = 'T':      Q**T * C       C * Q**T

       where Q is a real orthogonal matrix of order nq, with nq = m if SIDE  =
       'L'  and nq = n if SIDE = 'R'. Q is defined as the product of nq-1 ele-
       mentary reflectors, as returned by DSYTRD:

       if UPLO = 'U', Q = H(nq-1) . . . H(2) H(1);

       if UPLO = 'L', Q = H(1) H(2) . . . H(nq-1).


ARGUMENTS
       SIDE (input)
                 = 'L': apply Q or Q**T from the Left;
                 = 'R': apply Q or Q**T from the Right.


       UPLO (input)
                 = 'U': Upper triangle of  A  contains  elementary  reflectors
                 from  DSYTRD;  = 'L': Lower triangle of A contains elementary
                 reflectors from DSYTRD.


       TRANS (input)
                 = 'N':  No transpose, apply Q;
                 = 'T':  Transpose, apply Q**T.


       M (input) The number of rows of the matrix C. M >= 0.


       N (input) The number of columns of the matrix C. N >= 0.


       A (input) (LDA,M) if SIDE = 'L' (LDA,N) if SIDE = 'R' The vectors which
                 define the elementary reflectors, as returned by DSYTRD.


       LDA (input)
                 The  leading  dimension  of  the array A.  LDA >= max(1,M) if
                 SIDE = 'L'; LDA >= max(1,N) if SIDE = 'R'.


       TAU (input)
                 (M-1) if SIDE = 'L' (N-1) if SIDE = 'R' TAU(i)  must  contain
                 the  scalar  factor  of  the  elementary  reflector  H(i), as
                 returned by DSYTRD.


       C (input/output)
                 On entry, the M-by-N matrix C.  On exit, C is overwritten  by
                 Q*C or Q**T*C or C*Q**T or C*Q.


       LDC (input)
                 The leading dimension of the array C. LDC >= max(1,M).


       WORK (workspace)
                 On exit, if INFO = 0, WORK(1) returns the optimal LWORK.


       LWORK (input)
                 The  dimension  of  the  array WORK.  If SIDE = 'L', LWORK >=
                 max(1,N); if SIDE = 'R', LWORK >= max(1,M).  For optimum per-
                 formance  LWORK  >=  N*NB if SIDE = 'L', and LWORK >= M*NB if
                 SIDE = 'R', where NB is the optimal blocksize.

                 If LWORK = -1, then a workspace query is assumed; the routine
                 only  calculates  the optimal size of the WORK array, returns
                 this value as the first entry of the WORK array, and no error
                 message related to LWORK is issued by XERBLA.


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




                                  7 Nov 2015                        dormtr(3P)