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zgeqrt2.f(3) LAPACK zgeqrt2.f(3)

zgeqrt2.f -


subroutine zgeqrt2 (M, N, A, LDA, T, LDT, INFO)
 
ZGEQRT2 computes a QR factorization of a general real or complex matrix using the compact WY representation of Q.

ZGEQRT2 computes a QR factorization of a general real or complex matrix using the compact WY representation of Q.
Purpose:
 ZGEQRT2 computes a QR factorization of a complex M-by-N matrix A, 
 using the compact WY representation of Q. 
Parameters:
M
          M is INTEGER
          The number of rows of the matrix A.  M >= N.
N
          N is INTEGER
          The number of columns of the matrix A.  N >= 0.
A
          A is COMPLEX*16 array, dimension (LDA,N)
          On entry, the complex M-by-N matrix A.  On exit, the elements on and
          above the diagonal contain the N-by-N upper triangular matrix R; the
          elements below the diagonal are the columns of V.  See below for
          further details.
LDA
          LDA is INTEGER
          The leading dimension of the array A.  LDA >= max(1,M).
T
          T is COMPLEX*16 array, dimension (LDT,N)
          The N-by-N upper triangular factor of the block reflector.
          The elements on and above the diagonal contain the block
          reflector T; the elements below the diagonal are not used.
          See below for further details.
LDT
          LDT is INTEGER
          The leading dimension of the array T.  LDT >= max(1,N).
INFO
          INFO is INTEGER
          = 0: successful exit
          < 0: if INFO = -i, the i-th argument had an illegal value
Author:
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
September 2012
Further Details:
  The matrix V stores the elementary reflectors H(i) in the i-th column
  below the diagonal. For example, if M=5 and N=3, the matrix V is
V = ( 1 ) ( v1 1 ) ( v1 v2 1 ) ( v1 v2 v3 ) ( v1 v2 v3 )
where the vi's represent the vectors which define H(i), which are returned in the matrix A. The 1's along the diagonal of V are not stored in A. The block reflector H is then given by
H = I - V * T * V**H
where V**H is the conjugate transpose of V.
Definition at line 128 of file zgeqrt2.f.

Generated automatically by Doxygen for LAPACK from the source code.
Sat Nov 16 2013 Version 3.4.2

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