!>
!> SLACN2 estimates the 1-norm of a square, real matrix A.
!> Reverse communication is used for evaluating matrix-vector products.
!> 

N

!>          N is INTEGER
!>         The order of the matrix.  N >= 1.
!> 

V

!>          V is REAL array, dimension (N)
!>         On the final return, V = A*W,  where  EST = norm(V)/norm(W)
!>         (W is not returned).
!> 

X

!>          X is REAL array, dimension (N)
!>         On an intermediate return, X should be overwritten by
!>               A * X,   if KASE=1,
!>               A**T * X,  if KASE=2,
!>         and SLACN2 must be re-called with all the other parameters
!>         unchanged.
!> 

ISGN

!>          ISGN is INTEGER array, dimension (N)
!> 

EST

!>          EST is REAL
!>         On entry with KASE = 1 or 2 and ISAVE(1) = 3, EST should be
!>         unchanged from the previous call to SLACN2.
!>         On exit, EST is an estimate (a lower bound) for norm(A).
!> 

KASE

!>          KASE is INTEGER
!>         On the initial call to SLACN2, 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**T * X.
!>         On the final return from SLACN2, KASE will again be 0.
!> 

ISAVE

!>          ISAVE is INTEGER array, dimension (3)
!>         ISAVE is used to save variables between calls to SLACN2
!> 

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

!>
!>  Originally named SONEST, dated March 16, 1988.
!>
!>  This is a thread safe version of SLACON, which uses the array ISAVE
!>  in place of a SAVE statement, as follows:
!>
!>     SLACON     SLACN2
!>      JUMP     ISAVE(1)
!>      J        ISAVE(2)
!>      ITER     ISAVE(3)
!> 

Nick Higham, University of Manchester

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.