.TH "SRC/sgemqr.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*-
.ad l
.nh
.SH NAME
SRC/sgemqr.f
.SH SYNOPSIS
.br
.PP
.SS "Functions/Subroutines"

.in +1c
.ti -1c
.RI "subroutine \fBsgemqr\fP (side, trans, m, n, k, a, lda, t, tsize, c, ldc, work, lwork, info)"
.br
.RI "\fBSGEMQR\fP "
.in -1c
.SH "Function/Subroutine Documentation"
.PP 
.SS "subroutine sgemqr (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
\fBSGEMQR\fP 
.PP
\fBPurpose:\fP
.RS 4

.PP
.nf
!>
!> SGEMQR 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 tall skinny
!> QR factorization (SGEQR)
!>
!> 
.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,K)
!>          Part of the data structure to represent Q as returned by SGEQR\&.
!> 
.fi
.PP
.br
\fILDA\fP 
.PP
.nf
!>          LDA is INTEGER
!>          The leading dimension of the array A\&.
!>          If SIDE = 'L', LDA >= max(1,M);
!>          if SIDE = 'R', LDA >= max(1,N)\&.
!> 
.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 SGEQR\&.
!> 
.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) REAL array, dimension (MAX(1,LWORK))
!> 
.fi
.PP
.br
\fILWORK\fP 
.PP
.nf
!>          LWORK is INTEGER
!>          The dimension of the array WORK\&.
!>          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
!>                           SLATSQR or SGEQRT
!>
!>  Depending on the matrix dimensions M and N, and row and column
!>  block sizes MB and NB returned by ILAENV, SGEQR will use either
!>  SLATSQR (if the matrix is tall-and-skinny) or SGEQRT to compute
!>  the QR factorization\&.
!>  This version of SGEMQR will use either SLAMTSQR or SGEMQRT to
!>  multiply matrix Q by another matrix\&.
!>  Further Details in SLAMTSQR or SGEMQRT\&.
!>
!> 
.fi
.PP
 
.RE
.PP

.PP
Definition at line \fB172\fP of file \fBsgemqr\&.f\fP\&.
.SH "Author"
.PP 
Generated automatically by Doxygen for LAPACK from the source code\&.