cspcon (l)  Linux Man Pages
cspcon: 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 CSPTRF
Command to display cspcon
manual in Linux: $ man l cspcon
NAME
CSPCON  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 CSPTRF
SYNOPSIS
 SUBROUTINE CSPCON(

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

CHARACTER
UPLO

INTEGER
INFO, N

REAL
ANORM, RCOND

INTEGER
IPIV( * )

COMPLEX
AP( * ), WORK( * )
PURPOSE
CSPCON 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 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))).
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 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 (input) INTEGER array, dimension (N)

Details of the interchanges and the block structure of D
as determined by CSPTRF.
 ANORM (input) REAL

The 1norm of the original matrix A.
 RCOND (output) REAL

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 array, dimension (2*N)

 INFO (output) INTEGER

= 0: successful exit
< 0: if INFO = i, the ith argument had an illegal value
Pages related to cspcon
 cspcon (3)
 cspmv (l)  performs the matrixvector operation y := alpha*A*x + beta*y,
 cspr (l)  performs the symmetric rank 1 operation A := alpha*x*conjg( xaq ) + A,
 csprfs (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
 cspsv (l)  computes the solution to a complex system of linear equations A * X = B,
 cspsvx (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
 csptrf (l)  computes the factorization of a complex symmetric matrix A stored in packed format using the BunchKaufman diagonal pivoting method
 csptri (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 CSPTRF