.TH "SRC/zgeqr2p.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*-
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.SH NAME
SRC/zgeqr2p.f
.SH SYNOPSIS
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.SS "Functions/Subroutines"

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.ti -1c
.RI "subroutine \fBzgeqr2p\fP (m, n, a, lda, tau, work, info)"
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.RI "\fBZGEQR2P\fP computes the QR factorization of a general rectangular matrix with non-negative diagonal elements using an unblocked algorithm\&. "
.in -1c
.SH "Function/Subroutine Documentation"
.PP 
.SS "subroutine zgeqr2p (integer m, integer n, complex*16, dimension( lda, * ) a, integer lda, complex*16, dimension( * ) tau, complex*16, dimension( * ) work, integer info)"

.PP
\fBZGEQR2P\fP computes the QR factorization of a general rectangular matrix with non-negative diagonal elements using an unblocked algorithm\&.  
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\fBPurpose:\fP
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.nf
!>
!> ZGEQR2P computes a QR factorization of a complex m-by-n matrix A:
!>
!>    A = Q * ( R ),
!>            ( 0 )
!>
!> where:
!>
!>    Q is a m-by-m orthogonal matrix;
!>    R is an upper-triangular n-by-n matrix with nonnegative diagonal
!>    entries;
!>    0 is a (m-n)-by-n zero matrix, if m > n\&.
!>
!> 
.fi
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.RE
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\fBParameters\fP
.RS 4
\fIM\fP 
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!>          M is INTEGER
!>          The number of rows of the matrix A\&.  M >= 0\&.
!> 
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\fIN\fP 
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!>          N is INTEGER
!>          The number of columns of the matrix A\&.  N >= 0\&.
!> 
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\fIA\fP 
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!>          A is COMPLEX*16 array, dimension (LDA,N)
!>          On entry, the m by n matrix A\&.
!>          On exit, the elements on and above the diagonal of the array
!>          contain the min(m,n) by n upper trapezoidal matrix R (R is
!>          upper triangular if m >= n)\&. The diagonal entries of R
!>          are real and nonnegative; the elements below the diagonal,
!>          with the array TAU, represent the unitary matrix Q as a
!>          product of elementary reflectors (see Further Details)\&.
!> 
.fi
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\fILDA\fP 
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!>          LDA is INTEGER
!>          The leading dimension of the array A\&.  LDA >= max(1,M)\&.
!> 
.fi
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\fITAU\fP 
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!>          TAU is COMPLEX*16 array, dimension (min(M,N))
!>          The scalar factors of the elementary reflectors (see Further
!>          Details)\&.
!> 
.fi
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\fIWORK\fP 
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!>          WORK is COMPLEX*16 array, dimension (N)
!> 
.fi
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.br
\fIINFO\fP 
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!>          INFO is INTEGER
!>          = 0: successful exit
!>          < 0: if INFO = -i, the i-th argument had an illegal value
!> 
.fi
.PP
 
.RE
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\fBAuthor\fP
.RS 4
Univ\&. of Tennessee 

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Univ\&. of California Berkeley 

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Univ\&. of Colorado Denver 

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NAG Ltd\&. 
.RE
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\fBFurther Details:\fP
.RS 4

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.nf
!>
!>  The matrix Q is represented as a product of elementary reflectors
!>
!>     Q = H(1) H(2) \&. \&. \&. H(k), 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(1:i-1) = 0 and v(i) = 1; v(i+1:m) is stored on exit in A(i+1:m,i),
!>  and tau in TAU(i)\&.
!>
!> See Lapack Working Note 203 for details
!> 
.fi
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.RE
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Definition at line \fB133\fP of file \fBzgeqr2p\&.f\fP\&.
.SH "Author"
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Generated automatically by Doxygen for LAPACK from the source code\&.