table of contents
/home/abuild/rpmbuild/BUILD/lapack-3.12.0/TESTING/LIN/dqrt14.f(3) | Library Functions Manual | /home/abuild/rpmbuild/BUILD/lapack-3.12.0/TESTING/LIN/dqrt14.f(3) |
NAME¶
/home/abuild/rpmbuild/BUILD/lapack-3.12.0/TESTING/LIN/dqrt14.f
SYNOPSIS¶
Functions/Subroutines¶
double precision function DQRT14 (trans, m, n, nrhs, a,
lda, x, ldx, work, lwork)
DQRT14
Function/Subroutine Documentation¶
double precision function DQRT14 (character trans, integer m, integer n, integer nrhs, double precision, dimension( lda, * ) a, integer lda, double precision, dimension( ldx, * ) x, integer ldx, double precision, dimension( lwork ) work, integer lwork)¶
DQRT14
Purpose:
!> !> DQRT14 checks whether X is in the row space of A or A'. It does so !> by scaling both X and A such that their norms are in the range !> [sqrt(eps), 1/sqrt(eps)], then computing a QR factorization of [A,X] !> (if TRANS = 'T') or an LQ factorization of [A',X]' (if TRANS = 'N'), !> and returning the norm of the trailing triangle, scaled by !> MAX(M,N,NRHS)*eps. !>
Parameters
TRANS
!> TRANS is CHARACTER*1 !> = 'N': No transpose, check for X in the row space of A !> = 'T': Transpose, check for X in the row space of A'. !>
M
!> M is INTEGER !> The number of rows of the matrix A. !>
N
!> N is INTEGER !> The number of columns of the matrix A. !>
NRHS
!> NRHS is INTEGER !> The number of right hand sides, i.e., the number of columns !> of X. !>
A
!> A is DOUBLE PRECISION array, dimension (LDA,N) !> The M-by-N matrix A. !>
LDA
!> LDA is INTEGER !> The leading dimension of the array A. !>
X
!> X is DOUBLE PRECISION array, dimension (LDX,NRHS) !> If TRANS = 'N', the N-by-NRHS matrix X. !> IF TRANS = 'T', the M-by-NRHS matrix X. !>
LDX
!> LDX is INTEGER !> The leading dimension of the array X. !>
WORK
!> WORK is DOUBLE PRECISION array dimension (LWORK) !>
LWORK
!> LWORK is INTEGER !> length of workspace array required !> If TRANS = 'N', LWORK >= (M+NRHS)*(N+2); !> if TRANS = 'T', LWORK >= (N+NRHS)*(M+2). !>
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 114 of file dqrt14.f.
Author¶
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Version 3.12.0 | LAPACK |