cgeqrt.f(3) LAPACK cgeqrt.f(3)[top]NAMEcgeqrt.f-SYNOPSISFunctions/Subroutines subroutine cgeqrt (M, N, NB, A, LDA, T, LDT, WORK, INFO) CGEQRTFunction/Subroutine Documentation subroutine cgeqrt (integerM, integerN, integerNB, complex, dimension( lda, * )A, integerLDA, complex, dimension( ldt, * )T, integerLDT, complex, dimension( * )WORK, integerINFO) CGEQRT Purpose: CGEQRT computes a blocked 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 >= 0. N N is INTEGER The number of columns of the matrix A. N >= 0. NB NB is INTEGER The block size to be used in the blocked QR. MIN(M,N) >= NB >= 1. A A is COMPLEX 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 elements below the diagonal are the columns of V. LDA LDA is INTEGER The leading dimension of the array A. LDA >= max(1,M). T T is COMPLEX array, dimension (LDT,MIN(M,N)) The upper triangular block reflectors stored in compact form as a sequence of upper triangular blocks. See below for further details. LDT LDT is INTEGER The leading dimension of the array T. LDT >= NB. WORK WORK is COMPLEX array, dimension (NB*N) INFO INFO is INTEGER = 0: successful exit < 0: if INFO =, the i-th argument had an illegal value Author: Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Date: November 2011 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. Let K=MIN(M,N). The number of blocks is B = ceiling(K/NB), where each block is of order NB except for the last block, which is of order IB = K - (B-1)*NB. For each of the B blocks, a upper triangular block reflector factor is computed: T1, T2, ..., TB. The NB-by-NB (and IB-by-IB for the last block) T's are stored in the NB-by-N matrix T as T = (T1 T2 ... TB). Definition at line 142 of file cgeqrt.f.-iAuthorGenerated automatically by Doxygen for LAPACK from the source code.Version 3.4.2Tue Sep 25 2012 cgeqrt.f(3)

List of man pages available for

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]

Polar

Member of Polar

Based on Fawad Halim's script.

....................................................................

Vote for polarhome |