zspcon.f man page

zspcon.f

Synopsis

Functions/Subroutines

subroutine zspcon (UPLO, N, AP, IPIV, ANORM, RCOND, WORK, INFO)
ZSPCON

Function/Subroutine Documentation

subroutine zspcon (character UPLO, integer N, complex*16, dimension( * ) AP, integer, dimension( * ) IPIV, double precision ANORM, double precision RCOND, complex*16, dimension( * ) WORK, integer INFO)

ZSPCON  

Purpose:

 ZSPCON 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 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))).
Parameters:

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.

N

          N is INTEGER
          The order of the matrix A.  N >= 0.

AP

          AP is 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

          IPIV is INTEGER array, dimension (N)
          Details of the interchanges and the block structure of D
          as determined by ZSPTRF.

ANORM

          ANORM is DOUBLE PRECISION
          The 1-norm of the original matrix A.

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.

WORK

          WORK is COMPLEX*16 array, dimension (2*N)

INFO

          INFO is INTEGER
          = 0:  successful exit
          < 0:  if INFO = -i, the i-th argument had an illegal value
Author:

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date:

December 2016

Definition at line 120 of file zspcon.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

The man page zspcon(3) is an alias of zspcon.f(3).

Tue Nov 14 2017 Version 3.8.0 LAPACK