cspcon.f man page
cspcon.f subroutine cspcon (UPLO, N, AP, IPIV, ANORM, RCOND, WORK, INFO) CSPCON Purpose: UPLO N AP IPIV ANORM RCOND WORK INFO Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. December 2016 Definition at line 120 of file cspcon.f. Generated automatically by Doxygen for LAPACK from the source code. The man page cspcon(3) is an alias of cspcon.f(3).Synopsis
Functions/Subroutines
CSPCONFunction/Subroutine Documentation
subroutine cspcon (character UPLO, integer N, complex, dimension( * ) AP, integer, dimension( * ) IPIV, real ANORM, real RCOND, complex, dimension( * ) WORK, integer INFO)
CSPCON estimates the reciprocal of the condition number (in the
1-norm) of a complex symmetric packed matrix A using the
factorization A = U*D*U**T or A = L*D*L**T computed by CSPTRF.
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
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.
N is INTEGER
The order of the matrix A. N >= 0.
AP is COMPLEX array, dimension (N*(N+1)/2)
The block diagonal matrix D and the multipliers used to
obtain the factor U or L as computed by CSPTRF, stored as a
packed triangular matrix.
IPIV is INTEGER array, dimension (N)
Details of the interchanges and the block structure of D
as determined by CSPTRF.
ANORM is REAL
The 1-norm of the original 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 COMPLEX array, dimension (2*N)
INFO is INTEGER
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value
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