.TH "SRC/sgemlq.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME SRC/sgemlq.f .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "subroutine \fBsgemlq\fP (side, trans, m, n, k, a, lda, t, tsize, c, ldc, work, lwork, info)" .br .RI "\fBSGEMLQ\fP " .in -1c .SH "Function/Subroutine Documentation" .PP .SS "subroutine sgemlq (character side, character trans, integer m, integer n, integer k, real, dimension( lda, * ) a, integer lda, real, dimension( * ) t, integer tsize, real, dimension( ldc, * ) c, integer ldc, real, dimension( * ) work, integer lwork, integer info)" .PP \fBSGEMLQ\fP .PP \fBPurpose:\fP .RS 4 .PP .nf !> !> SGEMLQ 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 blocked elementary reflectors computed by short wide LQ !> factorization (SGELQ) !> !> .fi .PP .RE .PP \fBParameters\fP .RS 4 \fISIDE\fP .PP .nf !> SIDE is CHARACTER*1 !> = 'L': apply Q or Q**T from the Left; !> = 'R': apply Q or Q**T from the Right\&. !> .fi .PP .br \fITRANS\fP .PP .nf !> TRANS is CHARACTER*1 !> = 'N': No transpose, apply Q; !> = 'T': Transpose, apply Q**T\&. !> .fi .PP .br \fIM\fP .PP .nf !> M is INTEGER !> The number of rows of the matrix A\&. M >=0\&. !> .fi .PP .br \fIN\fP .PP .nf !> N is INTEGER !> The number of columns of the matrix C\&. N >= 0\&. !> .fi .PP .br \fIK\fP .PP .nf !> 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\&. !> .fi .PP .br \fIA\fP .PP .nf !> A is REAL array, dimension !> (LDA,M) if SIDE = 'L', !> (LDA,N) if SIDE = 'R' !> Part of the data structure to represent Q as returned by SGELQ\&. !> .fi .PP .br \fILDA\fP .PP .nf !> LDA is INTEGER !> The leading dimension of the array A\&. LDA >= max(1,K)\&. !> .fi .PP .br \fIT\fP .PP .nf !> T is REAL array, dimension (MAX(5,TSIZE))\&. !> Part of the data structure to represent Q as returned by SGELQ\&. !> .fi .PP .br \fITSIZE\fP .PP .nf !> TSIZE is INTEGER !> The dimension of the array T\&. TSIZE >= 5\&. !> .fi .PP .br \fIC\fP .PP .nf !> 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\&. !> .fi .PP .br \fILDC\fP .PP .nf !> LDC is INTEGER !> The leading dimension of the array C\&. LDC >= max(1,M)\&. !> .fi .PP .br \fIWORK\fP .PP .nf !> (workspace) DOUBLE PRECISION array, dimension (MAX(1,LWORK)) !> On exit, if INFO = 0, WORK(1) returns the minimal LWORK\&. !> .fi .PP .br \fILWORK\fP .PP .nf !> LWORK is INTEGER !> The dimension of the array WORK\&. LWORK >= 1\&. !> If LWORK = -1, then a workspace query is assumed\&. The routine !> only calculates the size of the WORK array, returns this !> value as WORK(1), and no error message related to WORK !> is issued by XERBLA\&. !> .fi .PP .br \fIINFO\fP .PP .nf !> INFO is INTEGER !> = 0: successful exit !> < 0: if INFO = -i, the i-th argument had an illegal value !> .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 \fBFurther Details\fP .RS 4 .PP .nf !> !> These details are particular for this LAPACK implementation\&. Users should not !> take them for granted\&. These details may change in the future, and are not likely !> true for another LAPACK implementation\&. These details are relevant if one wants !> to try to understand the code\&. They are not part of the interface\&. !> !> In this version, !> !> T(2): row block size (MB) !> T(3): column block size (NB) !> T(6:TSIZE): data structure needed for Q, computed by !> SLASWLQ or SGELQT !> !> Depending on the matrix dimensions M and N, and row and column !> block sizes MB and NB returned by ILAENV, SGELQ will use either !> SLASWLQ (if the matrix is wide-and-short) or SGELQT to compute !> the LQ factorization\&. !> This version of SGEMLQ will use either SLAMSWLQ or SGEMLQT to !> multiply matrix Q by another matrix\&. !> Further Details in SLAMSWLQ or SGEMLQT\&. !> .fi .PP .RE .PP .PP Definition at line \fB171\fP of file \fBsgemlq\&.f\fP\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.