#include <math.h>
#include "slu_Cnames.h"
#include "slu_scomplex.h"
Functions | |
int | clacon_ (int *n, complex *v, complex *x, float *est, int *kase) |
-- SuperLU routine (version 2.0) -- Univ. of California Berkeley, Xerox Palo Alto Research Center, and Lawrence Berkeley National Lab. November 15, 1997
Purpose =======
CLACON estimates the 1-norm of a square matrix A. Reverse communication is used for evaluating matrix-vector products.
Arguments =========
N (input) INT The order of the matrix. N >= 1.
V (workspace) COMPLEX PRECISION array, dimension (N) On the final return, V = A*W, where EST = norm(V)/norm(W) (W is not returned).
X (input/output) COMPLEX PRECISION array, dimension (N) On an intermediate return, X should be overwritten by A * X, if KASE=1, A' * X, if KASE=2, where A' is the conjugate transpose of A, and CLACON must be re-called with all the other parameters unchanged.
EST (output) FLOAT PRECISION An estimate (a lower bound) for norm(A).
KASE (input/output) INT 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' * X. On the final return from CLACON, KASE will again be 0.
Further Details ======= =======
Contributed by Nick Higham, University of Manchester. Originally named CONEST, dated March 16, 1988.
Reference: 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. =====================================================================