spocon.f man page
subroutine spocon (UPLO, N, A, LDA, ANORM, RCOND, WORK, IWORK, INFO)
subroutine spocon (characterUPLO, integerN, real, dimension( lda, * )A, integerLDA, realANORM, realRCOND, real, dimension( * )WORK, integer, dimension( * )IWORK, integerINFO)
SPOCON estimates the reciprocal of the condition number (in the 1-norm) of a real symmetric positive definite matrix using the Cholesky factorization A = U**T*U or A = L*L**T computed by SPOTRF. An estimate is obtained for norm(inv(A)), and the reciprocal of the condition number is computed as RCOND = 1 / (ANORM * norm(inv(A))).
UPLO is CHARACTER*1 = 'U': Upper triangle of A is stored; = 'L': Lower triangle of A is stored.
N is INTEGER The order of the matrix A. N >= 0.
A is REAL array, dimension (LDA,N) The triangular factor U or L from the Cholesky factorization A = U**T*U or A = L*L**T, as computed by SPOTRF.
LDA is INTEGER The leading dimension of the array A. LDA >= max(1,N).
ANORM is REAL The 1-norm (or infinity-norm) of the symmetric matrix A.
RCOND is REAL 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.
WORK is REAL array, dimension (3*N)
IWORK is INTEGER array, dimension (N)
INFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
Definition at line 121 of file spocon.f.
Generated automatically by Doxygen for LAPACK from the source code.
spocon(3) is an alias of spocon.f(3).