TESTING/MATGEN/slaror.f(3)                            Library Functions Manual

NAME
       TESTING/MATGEN/slaror.f

SYNOPSIS
   Functions/Subroutines
       subroutine slaror (side, init, m, n, a, lda, iseed, x, info)
           SLAROR

Function/Subroutine Documentation
   subroutine slaror (character side, character init, integer m, integer n,
       real, dimension( lda, * ) a, integer lda, integer, dimension( 4 )
       iseed, real, dimension( * ) x, integer info)
       SLAROR

       Purpose:


            SLAROR pre- or post-multiplies an M by N matrix A by a random
            orthogonal matrix U, overwriting A.  A may optionally be initialized
            to the identity matrix before multiplying by U.  U is generated using
            the method of G.W. Stewart (SIAM J. Numer. Anal. 17, 1980, 403-409).

       Parameters
           SIDE

                     SIDE is CHARACTER*1
                     Specifies whether A is multiplied on the left or right by U.
                     = 'L':         Multiply A on the left (premultiply) by U
                     = 'R':         Multiply A on the right (postmultiply) by U'
                     = 'C' or 'T':  Multiply A on the left by U and the right
                                     by U' (Here, U' means U-transpose.)

           INIT

                     INIT is CHARACTER*1
                     Specifies whether or not A should be initialized to the
                     identity matrix.
                     = 'I':  Initialize A to (a section of) the identity matrix
                              before applying U.
                     = 'N':  No initialization.  Apply U to the input matrix A.

                     INIT = 'I' may be used to generate square or rectangular
                     orthogonal matrices:

                     For M = N and SIDE = 'L' or 'R', the rows will be orthogonal
                     to each other, as will the columns.

                     If M < N, SIDE = 'R' produces a dense matrix whose rows are
                     orthogonal and whose columns are not, while SIDE = 'L'
                     produces a matrix whose rows are orthogonal, and whose first
                     M columns are orthogonal, and whose remaining columns are
                     zero.

                     If M > N, SIDE = 'L' produces a dense matrix whose columns
                     are orthogonal and whose rows are not, while SIDE = 'R'
                     produces a matrix whose columns are orthogonal, and whose
                     first M rows are orthogonal, and whose remaining rows are
                     zero.

           M

                     M is INTEGER
                     The number of rows of A.

           N

                     N is INTEGER
                     The number of columns of A.

           A

                     A is REAL array, dimension (LDA, N)
                     On entry, the array A.
                     On exit, overwritten by U A ( if SIDE = 'L' ),
                      or by A U ( if SIDE = 'R' ),
                      or by U A U' ( if SIDE = 'C' or 'T').

           LDA

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

           ISEED

                     ISEED is INTEGER array, dimension (4)
                     On entry ISEED specifies the seed of the random number
                     generator. The array elements should be between 0 and 4095;
                     if not they will be reduced mod 4096.  Also, ISEED(4) must
                     be odd.  The random number generator uses a linear
                     congruential sequence limited to small integers, and so
                     should produce machine independent random numbers. The
                     values of ISEED are changed on exit, and can be used in the
                     next call to SLAROR to continue the same random number
                     sequence.

           X

                     X is REAL array, dimension (3*MAX( M, N ))
                     Workspace of length
                         2*M + N if SIDE = 'L',
                         2*N + M if SIDE = 'R',
                         3*N     if SIDE = 'C' or 'T'.

           INFO

                     INFO is INTEGER
                     An error flag.  It is set to:
                     = 0:  normal return
                     < 0:  if INFO = -k, the k-th argument had an illegal value
                     = 1:  if the random numbers generated by SLARND are bad.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Definition at line 145 of file slaror.f.

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

LAPACK                          Version 3.12.0      TESTING/MATGEN/slaror.f(3)