zspcon (l)  Linux Man Pages
zspcon: estimates the reciprocal of the condition number (in the 1norm) of a complex symmetric packed matrix A using the factorization A = U*D*U**T or A = L*D*L**T computed by ZSPTRF
Command to display zspcon
manual in Linux: $ man l zspcon
NAME
ZSPCON  estimates the reciprocal of the condition number (in the 1norm) of a complex symmetric packed matrix A using the factorization A = U*D*U**T or A = L*D*L**T computed by ZSPTRF
SYNOPSIS
 SUBROUTINE ZSPCON(

UPLO, N, AP, IPIV, ANORM, RCOND, WORK, INFO )

CHARACTER
UPLO

INTEGER
INFO, N

DOUBLE
PRECISION ANORM, RCOND

INTEGER
IPIV( * )

COMPLEX*16
AP( * ), WORK( * )
PURPOSE
ZSPCON estimates the reciprocal of the condition number (in the
1norm) of a complex symmetric packed matrix A using the
factorization A = U*D*U**T or A = L*D*L**T computed by ZSPTRF.
An estimate is obtained for norm(inv(A)), and the reciprocal of the
condition number is computed as RCOND = 1 / (ANORM * norm(inv(A))).
ARGUMENTS
 UPLO (input) CHARACTER*1

Specifies whether the details of the factorization are stored
as an upper or lower triangular matrix.
= aqUaq: Upper triangular, form is A = U*D*U**T;
= aqLaq: Lower triangular, form is A = L*D*L**T.
 N (input) INTEGER

The order of the matrix A. N >= 0.
 AP (input) COMPLEX*16 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 ZSPTRF, stored as a
packed triangular matrix.
 IPIV (input) INTEGER array, dimension (N)

Details of the interchanges and the block structure of D
as determined by ZSPTRF.
 ANORM (input) DOUBLE PRECISION

The 1norm of the original matrix A.
 RCOND (output) 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 1norm of inv(A) computed in this routine.
 WORK (workspace) COMPLEX*16 array, dimension (2*N)

 INFO (output) INTEGER

= 0: successful exit
< 0: if INFO = i, the ith argument had an illegal value
Pages related to zspcon
 zspcon (3)
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 zspr (l)  performs the symmetric rank 1 operation A := alpha*x*conjg( xaq ) + A,
 zsprfs (l)  improves the computed solution to a system of linear equations when the coefficient matrix is symmetric indefinite and packed, and provides error bounds and backward error estimates for the solution
 zspsv (l)  computes the solution to a complex system of linear equations A * X = B,
 zspsvx (l)  uses the diagonal pivoting factorization A = U*D*U**T or A = L*D*L**T to compute the solution to a complex system of linear equations A * X = B, where A is an NbyN symmetric matrix stored in packed format and X and B are NbyNRHS matrices
 zsptrf (l)  computes the factorization of a complex symmetric matrix A stored in packed format using the BunchKaufman diagonal pivoting method
 zsptri (l)  computes the inverse of a complex symmetric indefinite matrix A in packed storage using the factorization A = U*D*U**T or A = L*D*L**T computed by ZSPTRF