SRC/sorm2r.f(3)            Library Functions Manual            SRC/sorm2r.f(3)

NAME
       SRC/sorm2r.f

SYNOPSIS
   Functions/Subroutines
       subroutine sorm2r (side, trans, m, n, k, a, lda, tau, c, ldc, work,
           info)
           SORM2R multiplies a general matrix by the orthogonal matrix from a
           QR factorization determined by sgeqrf (unblocked algorithm).

Function/Subroutine Documentation
   subroutine sorm2r (character side, character trans, integer m, integer n,
       integer k, real, dimension( lda, * ) a, integer lda, real, dimension( *
       ) tau, real, dimension( ldc, * ) c, integer ldc, real, dimension( * )
       work, integer info)
       SORM2R multiplies a general matrix by the orthogonal matrix from a QR
       factorization determined by sgeqrf (unblocked algorithm).

       Purpose:


            SORM2R overwrites the general real m by n matrix C with

                  Q * C  if SIDE = 'L' and TRANS = 'N', or

                  Q**T* C  if SIDE = 'L' and TRANS = 'T', or

                  C * Q  if SIDE = 'R' and TRANS = 'N', or

                  C * Q**T if SIDE = 'R' and TRANS = 'T',

            where Q is a real orthogonal matrix defined as the product of k
            elementary reflectors

                  Q = H(1) H(2) . . . H(k)

            as returned by SGEQRF. 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': apply Q  (No transpose)
                     = 'T': apply Q**T (Transpose)

           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.

           A

                     A is REAL array, dimension (LDA,K)
                     The i-th column must contain the vector which defines the
                     elementary reflector H(i), for i = 1,2,...,k, as returned by
                     SGEQRF in the first k columns of its array argument A.
                     A is modified by the routine but restored on exit.

           LDA

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

           TAU

                     TAU is REAL array, dimension (K)
                     TAU(i) must contain the scalar factor of the elementary
                     reflector H(i), as returned by SGEQRF.

           C

                     C is REAL array, dimension (LDC,N)
                     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

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

           WORK

                     WORK is REAL array, dimension
                                              (N) if SIDE = 'L',
                                              (M) 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 157 of file sorm2r.f.

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

LAPACK                          Version 3.12.0                 SRC/sorm2r.f(3)