table of contents
/home/abuild/rpmbuild/BUILD/lapack-3.12.0/SRC/DEPRECATED/dgeqpf.f(3) | Library Functions Manual | /home/abuild/rpmbuild/BUILD/lapack-3.12.0/SRC/DEPRECATED/dgeqpf.f(3) |
NAME¶
/home/abuild/rpmbuild/BUILD/lapack-3.12.0/SRC/DEPRECATED/dgeqpf.f
SYNOPSIS¶
Functions/Subroutines¶
subroutine DGEQPF (m, n, a, lda, jpvt, tau, work, info)
DGEQPF
Function/Subroutine Documentation¶
subroutine DGEQPF (integer m, integer n, double precision, dimension( lda, * ) a, integer lda, integer, dimension( * ) jpvt, double precision, dimension( * ) tau, double precision, dimension( * ) work, integer info)¶
DGEQPF
Purpose:
!> !> This routine is deprecated and has been replaced by routine DGEQP3. !> !> DGEQPF computes a QR factorization with column pivoting of a !> real M-by-N matrix A: A*P = Q*R. !>
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 !>
A
!> A is DOUBLE PRECISION array, dimension (LDA,N) !> On entry, the M-by-N matrix A. !> On exit, the upper triangle of the array contains the !> min(M,N)-by-N upper triangular matrix R; the elements !> below the diagonal, together with the array TAU, !> represent the orthogonal matrix Q as a product of !> min(m,n) elementary reflectors. !>
LDA
!> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,M). !>
JPVT
!> 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. !>
TAU
!> TAU is DOUBLE PRECISION array, dimension (min(M,N)) !> The scalar factors of the elementary reflectors. !>
WORK
!> WORK is DOUBLE PRECISION array, dimension (3*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.
Further Details:
!> !> The matrix Q is represented as a product of elementary reflectors !> !> Q = H(1) H(2) . . . H(n) !> !> Each H(i) has the form !> !> H = I - tau * v * v**T !> !> where tau is a real scalar, and v is a real vector with !> v(1:i-1) = 0 and v(i) = 1; v(i+1:m) is stored on exit in A(i+1:m,i). !> !> The matrix P is represented in jpvt as follows: If !> jpvt(j) = i !> then the jth column of P is the ith canonical unit vector. !> !> Partial column norm updating strategy modified by !> Z. Drmac and Z. Bujanovic, Dept. of Mathematics, !> University of Zagreb, Croatia. !> -- April 2011 -- !> For more details see LAPACK Working Note 176. !>
Definition at line 141 of file dgeqpf.f.
Author¶
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