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CentOS 7.0 - man page for cgeqrt2 (centos section 3)

cgeqrt2.f(3)							      LAPACK							      cgeqrt2.f(3)

NAME
cgeqrt2.f -
SYNOPSIS
Functions/Subroutines subroutine cgeqrt2 (M, N, A, LDA, T, LDT, INFO) CGEQRT2 computes a QR factorization of a general real or complex matrix using the compact WY representation of Q. Function/Subroutine Documentation subroutine cgeqrt2 (integerM, integerN, complex, dimension( lda, * )A, integerLDA, complex, dimension( ldt, * )T, integerLDT, integerINFO) CGEQRT2 computes a QR factorization of a general real or complex matrix using the compact WY representation of Q. Purpose: CGEQRT2 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 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 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 cgeqrt2.f. Author Generated automatically by Doxygen for LAPACK from the source code. Version 3.4.2 Tue Sep 25 2012 cgeqrt2.f(3)