.TH "SRC/zgerq2.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*-
.ad l
.nh
.SH NAME
SRC/zgerq2.f
.SH SYNOPSIS
.br
.PP
.SS "Functions/Subroutines"

.in +1c
.ti -1c
.RI "subroutine \fBzgerq2\fP (m, n, a, lda, tau, work, info)"
.br
.RI "\fBZGERQ2\fP computes the RQ factorization of a general rectangular matrix using an unblocked algorithm\&. "
.in -1c
.SH "Function/Subroutine Documentation"
.PP 
.SS "subroutine zgerq2 (integer m, integer n, complex*16, dimension( lda, * ) a, integer lda, complex*16, dimension( * ) tau, complex*16, dimension( * ) work, integer info)"

.PP
\fBZGERQ2\fP computes the RQ factorization of a general rectangular matrix using an unblocked algorithm\&.  
.PP
\fBPurpose:\fP
.RS 4

.PP
.nf
!>
!> ZGERQ2 computes an RQ factorization of a complex m by n matrix A:
!> A = R * Q\&.
!> 
.fi
.PP
 
.RE
.PP
\fBParameters\fP
.RS 4
\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 A\&.  N >= 0\&.
!> 
.fi
.PP
.br
\fIA\fP 
.PP
.nf
!>          A is COMPLEX*16 array, dimension (LDA,N)
!>          On entry, the m by n matrix A\&.
!>          On exit, if m <= n, the upper triangle of the subarray
!>          A(1:m,n-m+1:n) contains the m by m upper triangular matrix R;
!>          if m >= n, the elements on and above the (m-n)-th subdiagonal
!>          contain the m by n upper trapezoidal matrix R; the remaining
!>          elements, with the array TAU, represent the unitary matrix
!>          Q as a product of elementary reflectors (see Further
!>          Details)\&.
!> 
.fi
.PP
.br
\fILDA\fP 
.PP
.nf
!>          LDA is INTEGER
!>          The leading dimension of the array A\&.  LDA >= max(1,M)\&.
!> 
.fi
.PP
.br
\fITAU\fP 
.PP
.nf
!>          TAU is COMPLEX*16 array, dimension (min(M,N))
!>          The scalar factors of the elementary reflectors (see Further
!>          Details)\&.
!> 
.fi
.PP
.br
\fIWORK\fP 
.PP
.nf
!>          WORK is COMPLEX*16 array, dimension (M)
!> 
.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
!>
!>  The matrix Q is represented as a product of elementary reflectors
!>
!>     Q = H(1)**H H(2)**H \&. \&. \&. H(k)**H, where k = min(m,n)\&.
!>
!>  Each H(i) has the form
!>
!>     H(i) = I - tau * v * v**H
!>
!>  where tau is a complex scalar, and v is a complex vector with
!>  v(n-k+i+1:n) = 0 and v(n-k+i) = 1; conjg(v(1:n-k+i-1)) is stored on
!>  exit in A(m-k+i,1:n-k+i-1), and tau in TAU(i)\&.
!> 
.fi
.PP
 
.RE
.PP

.PP
Definition at line \fB122\fP of file \fBzgerq2\&.f\fP\&.
.SH "Author"
.PP 
Generated automatically by Doxygen for LAPACK from the source code\&.