.TH "zlaqp2.f" 3 "Tue Nov 14 2017" "Version 3.8.0" "LAPACK" \" -*- nroff -*-
.ad l
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.SH NAME
zlaqp2.f
.SH SYNOPSIS
.br
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.SS "Functions/Subroutines"

.in +1c
.ti -1c
.RI "subroutine \fBzlaqp2\fP (M, \fBN\fP, OFFSET, A, \fBLDA\fP, JPVT, TAU, VN1, VN2, WORK)"
.br
.RI "\fBZLAQP2\fP computes a QR factorization with column pivoting of the matrix block\&. "
.in -1c
.SH "Function/Subroutine Documentation"
.PP 
.SS "subroutine zlaqp2 (integer M, integer N, integer OFFSET, complex*16, dimension( lda, * ) A, integer LDA, integer, dimension( * ) JPVT, complex*16, dimension( * ) TAU, double precision, dimension( * ) VN1, double precision, dimension( * ) VN2, complex*16, dimension( * ) WORK)"

.PP
\fBZLAQP2\fP computes a QR factorization with column pivoting of the matrix block\&.  
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\fBPurpose: \fP
.RS 4

.PP
.nf
 ZLAQP2 computes a QR factorization with column pivoting of
 the block A(OFFSET+1:M,1:N).
 The block A(1:OFFSET,1:N) is accordingly pivoted, but not factorized.
.fi
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.RE
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\fBParameters:\fP
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\fIM\fP 
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          M is INTEGER
          The number of rows of the matrix A. M >= 0.
.fi
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\fIN\fP 
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          N is INTEGER
          The number of columns of the matrix A. N >= 0.
.fi
.PP
.br
\fIOFFSET\fP 
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          OFFSET is INTEGER
          The number of rows of the matrix A that must be pivoted
          but no factorized. OFFSET >= 0.
.fi
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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 upper triangle of block A(OFFSET+1:M,1:N) is
          the triangular factor obtained; the elements in block
          A(OFFSET+1:M,1:N) below the diagonal, together with the
          array TAU, represent the orthogonal matrix Q as a product of
          elementary reflectors. Block A(1:OFFSET,1:N) has been
          accordingly pivoted, but no factorized.
.fi
.PP
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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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.br
\fIJPVT\fP 
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          JPVT is INTEGER array, dimension (N)
          On entry, if JPVT(i) .ne. 0, the i-th column of A is permuted
          to the front of A*P (a leading column); if JPVT(i) = 0,
          the i-th column of A is a free column.
          On exit, if JPVT(i) = k, then the i-th column of A*P
          was the k-th column of A.
.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.
.fi
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\fIVN1\fP 
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          VN1 is DOUBLE PRECISION array, dimension (N)
          The vector with the partial column norms.
.fi
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\fIVN2\fP 
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          VN2 is DOUBLE PRECISION array, dimension (N)
          The vector with the exact column norms.
.fi
.PP
.br
\fIWORK\fP 
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          WORK is COMPLEX*16 array, dimension (N)
.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\&. 
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\fBDate:\fP
.RS 4
December 2016 
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\fBContributors: \fP
.RS 4
G\&. Quintana-Orti, Depto\&. de Informatica, Universidad Jaime I, Spain X\&. Sun, Computer Science Dept\&., Duke University, USA 
.br
 Partial column norm updating strategy modified on April 2011 Z\&. Drmac and Z\&. Bujanovic, Dept\&. of Mathematics, University of Zagreb, Croatia\&. 
.RE
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\fBReferences: \fP
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LAPACK Working Note 176  
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Definition at line 151 of file zlaqp2\&.f\&.
.SH "Author"
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Generated automatically by Doxygen for LAPACK from the source code\&.
