.TH "zgerq2.f" 3 "Wed Oct 15 2014" "Version 3.4.2" "LAPACK" \" -*- nroff -*-
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.SH NAME
zgerq2.f \- 
.SH SYNOPSIS
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.SS "Functions/Subroutines"

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.RI "subroutine \fBzgerq2\fP (M, N, A, LDA, TAU, WORK, INFO)"
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.RI "\fI\fBZGERQ2\fP computes the RQ factorization of a general rectangular matrix using an unblocked algorithm\&. \fP"
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.SH "Function/Subroutine Documentation"
.PP 
.SS "subroutine zgerq2 (integerM, integerN, complex*16, dimension( lda, * )A, integerLDA, complex*16, dimension( * )TAU, complex*16, dimension( * )WORK, integerINFO)"

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

.PP
.nf
 ZGERQ2 computes an RQ factorization of a complex m by n matrix A:
 A = R * Q.
.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.
.fi
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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, 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
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\fILDA\fP 
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          LDA is INTEGER
          The leading dimension of the array A.  LDA >= max(1,M).
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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).
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\fIWORK\fP 
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          WORK is COMPLEX*16 array, dimension (M)
.fi
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\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
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.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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\fBDate:\fP
.RS 4
September 2012 
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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 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
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.RE
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Definition at line 124 of file zgerq2\&.f\&.
.SH "Author"
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Generated automatically by Doxygen for LAPACK from the source code\&.