====================================================================
dlacon examples
====================================================================

====================================================================
Man Page Details
====================================================================

NAME
       DLACON - the 1-norm of a square, real matrix A

SYNOPSIS
       SUBROUTINE DLACON( N, V, X, ISGN, EST, KASE )

           INTEGER        KASE, N

           DOUBLE         PRECISION EST

           INTEGER        ISGN( * )

           DOUBLE         PRECISION V( * ), X( * )

PURPOSE
       DLACON estimates the 1-norm of a square, real matrix A.  Reverse commu-
       nication is used for evaluating matrix-vector products.


ARGUMENTS
       N      (input) INTEGER
              The order of the matrix.  N >= 1.

       V      (workspace) DOUBLE PRECISION array, dimension (N)
              On the final return, V = A*W,  where  EST =  norm(V)/norm(W)  (W
              is not returned).

       X      (input/output) DOUBLE PRECISION array, dimension (N)
              On  an  intermediate  return,  X should be overwritten by A * X,
              if KASE=1, A' * X,  if KASE=2, and DLACON must be re-called with
              all the other parameters unchanged.

       ISGN   (workspace) INTEGER array, dimension (N)

       EST    (input/output) DOUBLE PRECISION
              On  entry  with  KASE  =  1  or  2  and  JUMP = 3, EST should be
              unchanged from the previous call to DLACON.  On exit, EST is  an
              estimate (a lower bound) for norm(A).

       KASE   (input/output) INTEGER
              On the initial call to DLACON, KASE should be 0.  On an interme-
              diate return, KASE will be 1 or 2, indicating whether  X  should
              be  overwritten  by  A * X  or A' * X.  On the final return from
              DLACON, KASE will again be 0.

FURTHER DETAILS
       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.

