.TH "TESTING/MATGEN/slaror.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME TESTING/MATGEN/slaror.f .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "subroutine \fBslaror\fP (side, init, m, n, a, lda, iseed, x, info)" .br .RI "\fBSLAROR\fP " .in -1c .SH "Function/Subroutine Documentation" .PP .SS "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)" .PP \fBSLAROR\fP .PP \fBPurpose:\fP .RS 4 .PP .nf !> !> 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)\&. !> .fi .PP .RE .PP \fBParameters\fP .RS 4 \fISIDE\fP .PP .nf !> 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\&.) !> .fi .PP .br \fIINIT\fP .PP .nf !> 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\&. !> .fi .PP .br \fIM\fP .PP .nf !> M is INTEGER !> The number of rows of A\&. !> .fi .PP .br \fIN\fP .PP .nf !> N is INTEGER !> The number of columns of A\&. !> .fi .PP .br \fIA\fP .PP .nf !> 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')\&. !> .fi .PP .br \fILDA\fP .PP .nf !> LDA is INTEGER !> The leading dimension of the array A\&. LDA >= max(1,M)\&. !> .fi .PP .br \fIISEED\fP .PP .nf !> 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\&. !> .fi .PP .br \fIX\fP .PP .nf !> 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'\&. !> .fi .PP .br \fIINFO\fP .PP .nf !> 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\&. !> .fi .PP .RE .PP \fBAuthor\fP .RS 4 Univ\&. of Tennessee .PP Univ\&. of California Berkeley .PP Univ\&. of Colorado Denver .PP NAG Ltd\&. .RE .PP .PP Definition at line \fB145\fP of file \fBslaror\&.f\fP\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.