SRC/dgemqrt.f(3)           Library Functions Manual           SRC/dgemqrt.f(3)

NAME
       SRC/dgemqrt.f

SYNOPSIS
   Functions/Subroutines
       subroutine dgemqrt (side, trans, m, n, k, nb, v, ldv, t, ldt, c, ldc,
           work, info)
           DGEMQRT

Function/Subroutine Documentation
   subroutine dgemqrt (character side, character trans, integer m, integer n,
       integer k, integer nb, double precision, dimension( ldv, * ) v, integer
       ldv, double precision, dimension( ldt, * ) t, integer ldt, double
       precision, dimension( ldc, * ) c, integer ldc, double precision,
       dimension( * ) work, integer info)
       DGEMQRT

       Purpose:


           !>
           !> DGEMQRT 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 defined as the product of K
           !> elementary reflectors:
           !>
           !>       Q = H(1) H(2) . . . H(K) = I - V T V**T
           !>
           !> generated using the compact WY representation as returned by DGEQRT.
           !>
           !> Q is of order M if SIDE = 'L' and of order N  if SIDE = 'R'.
           !>

       Parameters
           SIDE

           !>          SIDE is CHARACTER*1
           !>          = 'L': apply Q or Q**T from the Left;
           !>          = 'R': apply Q or Q**T from the Right.
           !>

           TRANS

           !>          TRANS is CHARACTER*1
           !>          = 'N':  No transpose, apply Q;
           !>          = 'C':  Transpose, apply Q**T.
           !>

           M

           !>          M is INTEGER
           !>          The number of rows of the matrix C. M >= 0.
           !>

           N

           !>          N is INTEGER
           !>          The number of columns of the matrix C. N >= 0.
           !>

           K

           !>          K is INTEGER
           !>          The number of elementary reflectors whose product defines
           !>          the matrix Q.
           !>          If SIDE = 'L', M >= K >= 0;
           !>          if SIDE = 'R', N >= K >= 0.
           !>

           NB

           !>          NB is INTEGER
           !>          The block size used for the storage of T.  K >= NB >= 1.
           !>          This must be the same value of NB used to generate T
           !>          in DGEQRT.
           !>

           V

           !>          V is DOUBLE PRECISION array, dimension (LDV,K)
           !>          The i-th column must contain the vector which defines the
           !>          elementary reflector H(i), for i = 1,2,...,k, as returned by
           !>          DGEQRT in the first K columns of its array argument A.
           !>

           LDV

           !>          LDV is INTEGER
           !>          The leading dimension of the array V.
           !>          If SIDE = 'L', LDA >= max(1,M);
           !>          if SIDE = 'R', LDA >= max(1,N).
           !>

           T

           !>          T is DOUBLE PRECISION array, dimension (LDT,K)
           !>          The upper triangular factors of the block reflectors
           !>          as returned by DGEQRT, stored as a NB-by-N matrix.
           !>

           LDT

           !>          LDT is INTEGER
           !>          The leading dimension of the array T.  LDT >= NB.
           !>

           C

           !>          C is DOUBLE PRECISION array, dimension (LDC,N)
           !>          On entry, the M-by-N matrix C.
           !>          On exit, C is overwritten by Q C, Q**T C, C Q**T or C Q.
           !>

           LDC

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

           WORK

           !>          WORK is DOUBLE PRECISION array. The dimension of
           !>          WORK is N*NB if SIDE = 'L', or  M*NB if SIDE = 'R'.
           !>

           INFO

           !>          INFO is INTEGER
           !>          = 0:  successful exit
           !>          < 0:  if INFO = -i, the i-th argument had an illegal value
           !>

       Author
           Univ. of Tennessee


           Univ. of California Berkeley


           Univ. of Colorado Denver


           NAG Ltd.

       Definition at line 166 of file dgemqrt.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

LAPACK                          Version 3.12.0                SRC/dgemqrt.f(3)