zqrt12.f3
Usage
Functions/Subroutines
double precision function zqrt12 (m, n, a, lda, s, work, lwork, rwork)
ZQRT12
Function/Subroutine Documentation
double precision function zqrt12 (integer m, integer n, complex*16, dimension( lda, * ) a, integer lda, double precision, dimension( * ) s, complex*16, dimension( lwork ) work, integer lwork, double precision, dimension( * ) rwork)
ZQRT12
Purpose:
!> !> ZQRT12 computes the singular values `svlues' of the upper trapezoid !> of A(1:M,1:N) and returns the ratio !> !> || svlues - s||/(||s||*eps*max(M,N)) !>
Parameters
M
!> M is INTEGER !> The number of rows of the matrix A. !>
N
!> N is INTEGER !> The number of columns of the matrix A. !>
A
!> A is COMPLEX*16 array, dimension (LDA,N) !> The M-by-N matrix A. Only the upper trapezoid is referenced. !>
LDA
!> LDA is INTEGER !> The leading dimension of the array A. !>
S
!> S is DOUBLE PRECISION array, dimension (min(M,N)) !> The singular values of the matrix A. !>
WORK
!> WORK is COMPLEX*16 array, dimension (LWORK) !>
LWORK
!> LWORK is INTEGER !> The length of the array WORK. LWORK >= M*N + 2*min(M,N) + !> max(M,N). !>
RWORK
!> RWORK is DOUBLE PRECISION array, dimension (2*min(M,N)) !>
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 95 of file zqrt12.f.