LAPACK 3.12.1
LAPACK: Linear Algebra PACKage
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subroutine dsycon_rook | ( | character | uplo, |
integer | n, | ||
double precision, dimension( lda, * ) | a, | ||
integer | lda, | ||
integer, dimension( * ) | ipiv, | ||
double precision | anorm, | ||
double precision | rcond, | ||
double precision, dimension( * ) | work, | ||
integer, dimension( * ) | iwork, | ||
integer | info ) |
DSYCON_ROOK
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!> !> DSYCON_ROOK estimates the reciprocal of the condition number (in the !> 1-norm) of a real symmetric matrix A using the factorization !> A = U*D*U**T or A = L*D*L**T computed by DSYTRF_ROOK. !> !> An estimate is obtained for norm(inv(A)), and the reciprocal of the !> condition number is computed as RCOND = 1 / (ANORM * norm(inv(A))). !>
[in] | UPLO | !> UPLO is CHARACTER*1 !> Specifies whether the details of the factorization are stored !> as an upper or lower triangular matrix. !> = 'U': Upper triangular, form is A = U*D*U**T; !> = 'L': Lower triangular, form is A = L*D*L**T. !> |
[in] | N | !> N is INTEGER !> The order of the matrix A. N >= 0. !> |
[in] | A | !> A is DOUBLE PRECISION array, dimension (LDA,N) !> The block diagonal matrix D and the multipliers used to !> obtain the factor U or L as computed by DSYTRF_ROOK. !> |
[in] | LDA | !> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,N). !> |
[in] | IPIV | !> IPIV is INTEGER array, dimension (N) !> Details of the interchanges and the block structure of D !> as determined by DSYTRF_ROOK. !> |
[in] | ANORM | !> ANORM is DOUBLE PRECISION !> The 1-norm of the original matrix A. !> |
[out] | RCOND | !> RCOND is DOUBLE PRECISION !> The reciprocal of the condition number of the matrix A, !> computed as RCOND = 1/(ANORM * AINVNM), where AINVNM is an !> estimate of the 1-norm of inv(A) computed in this routine. !> |
[out] | WORK | !> WORK is DOUBLE PRECISION array, dimension (2*N) !> |
[out] | IWORK | !> IWORK is INTEGER array, dimension (N) !> |
[out] | INFO | !> INFO is INTEGER !> = 0: successful exit !> < 0: if INFO = -i, the i-th argument had an illegal value !> |
!> !> April 2012, Igor Kozachenko, !> Computer Science Division, !> University of California, Berkeley !> !> September 2007, Sven Hammarling, Nicholas J. Higham, Craig Lucas, !> School of Mathematics, !> University of Manchester !> !>
Definition at line 140 of file dsycon_rook.f.