SRC/clacon.f(3) | Library Functions Manual | SRC/clacon.f(3) |
NAME
SRC/clacon.f
SYNOPSIS
Functions/Subroutines
subroutine clacon (n, v, x, est, kase)
CLACON estimates the 1-norm of a square matrix, using reverse
communication for evaluating matrix-vector products.
Function/Subroutine Documentation
subroutine clacon (integer n, complex, dimension( n ) v, complex, dimension( n ) x, real est, integer kase)
CLACON estimates the 1-norm of a square matrix, using reverse communication for evaluating matrix-vector products.
Purpose:
!> !> CLACON estimates the 1-norm of a square, complex matrix A. !> Reverse communication is used for evaluating matrix-vector products. !>
Parameters
N
!> N is INTEGER !> The order of the matrix. N >= 1. !>
V
!> V is COMPLEX array, dimension (N) !> On the final return, V = A*W, where EST = norm(V)/norm(W) !> (W is not returned). !>
X
!> X is COMPLEX array, dimension (N) !> On an intermediate return, X should be overwritten by !> A * X, if KASE=1, !> A**H * X, if KASE=2, !> where A**H is the conjugate transpose of A, and CLACON must be !> re-called with all the other parameters unchanged. !>
EST
!> EST is REAL !> On entry with KASE = 1 or 2 and JUMP = 3, EST should be !> unchanged from the previous call to CLACON. !> On exit, EST is an estimate (a lower bound) for norm(A). !>
KASE
!> KASE is INTEGER !> On the initial call to CLACON, KASE should be 0. !> On an intermediate return, KASE will be 1 or 2, indicating !> whether X should be overwritten by A * X or A**H * X. !> On the final return from CLACON, KASE will again be 0. !>
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Further Details:
Originally named CONEST, dated March 16, 1988.
Last modified: April, 1999
Last modified: April, 1999
Contributors:
Nick Higham, University of Manchester
References:
N.J. Higham, "FORTRAN codes for estimating the
one-norm of a real or complex matrix, with applications to condition
estimation", ACM Trans. Math. Soft., vol. 14, no. 4, pp. 381-396,
December 1988.
Definition at line 113 of file clacon.f.
Author
Generated automatically by Doxygen for LAPACK from the source code.
Version 3.12.0 | LAPACK |