RedHat 9 (Linux i386) - man page for dlacon (redhat section l)

Linux & Unix Commands - Search Man Pages

Man Page or Keyword Search:   man
Select Man Page Set:       apropos Keyword Search (sections above)


DLACON(l)					)					DLACON(l)

NAME
       DLACON - estimate 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 communication 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    (output) DOUBLE PRECISION
	      An estimate (a lower bound) for norm(A).

       KASE   (input/output) INTEGER
	      On  the  initial call to DLACON, 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 DLACON, KASE will again be 0.

FURTHER DETAILS
       Contributed by Nick Higham, University of Manchester.
       Originally named SONEST, 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.

LAPACK version 3.0			   15 June 2000 				DLACON(l)
Unix & Linux Commands & Man Pages : ©2000 - 2018 Unix and Linux Forums


All times are GMT -4. The time now is 08:49 AM.

Unix & Linux Forums Content Copyright©1993-2018. All Rights Reserved.
×
UNIX.COM Login
Username:
Password:  
Show Password





Not a Forum Member?
Forgot Password?