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

.in +1c
.ti -1c
.RI "subroutine \fBcgemqr\fP (side, trans, m, n, k, a, lda, t, tsize, c, ldc, work, lwork, info)"
.br
.RI "\fBCGEMQR\fP "
.in -1c
.SH "Function/Subroutine Documentation"
.PP 
.SS "subroutine cgemqr (character side, character trans, integer m, integer n, integer k, complex, dimension( lda, * ) a, integer lda, complex, dimension( * ) t, integer tsize, complex, dimension( ldc, * ) c, integer ldc, complex, dimension( * ) work, integer lwork, integer info)"

.PP
\fBCGEMQR\fP 
.PP
\fBPurpose:\fP
.RS 4

.PP
.nf
 CGEMQR overwrites the general real M-by-N matrix C with

                      SIDE = 'L'     SIDE = 'R'
      TRANS = 'N':      Q * C          C * Q
      TRANS = 'T':      Q**H * C       C * Q**H

 where Q is a complex unitary matrix defined as the product
 of blocked elementary reflectors computed by tall skinny
 QR factorization (CGEQR)
.fi
.PP
 
.RE
.PP
\fBParameters\fP
.RS 4
\fISIDE\fP 
.PP
.nf
          SIDE is CHARACTER*1
          = 'L': apply Q or Q**H from the Left;
          = 'R': apply Q or Q**H from the Right\&.
.fi
.PP
.br
\fITRANS\fP 
.PP
.nf
          TRANS is CHARACTER*1
          = 'N':  No transpose, apply Q;
          = 'C':  Conjugate transpose, apply Q**H\&.
.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 COMPLEX array, dimension (LDA,K)
          Part of the data structure to represent Q as returned by CGEQR\&.
.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 COMPLEX array, dimension (MAX(5,TSIZE))\&.
          Part of the data structure to represent Q as returned by CGEQR\&.
.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 COMPLEX array, dimension (LDC,N)
          On entry, the M-by-N matrix C\&.
          On exit, C is overwritten by Q*C or Q**H*C or C*Q**H 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) COMPLEX 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
                           CLATSQR or CGEQRT

  Depending on the matrix dimensions M and N, and row and column
  block sizes MB and NB returned by ILAENV, CGEQR will use either
  CLATSQR (if the matrix is tall-and-skinny) or CGEQRT to compute
  the QR factorization\&.
  This version of CGEMQR will use either CLAMTSQR or CGEMQRT to
  multiply matrix Q by another matrix\&.
  Further Details in CLAMTSQR or CGEMQRT\&.
.fi
.PP
 
.RE
.PP

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