function p = amdbar (S)
% AMDBAR Symmetric approximate minimum degree permutation.
%    P = AMDBAR (S), for a symmetric positive definite matrix S,
%    returns the permutation vector p such that S(p,p) tends to have a
%    sparser Cholesky factor than S.  Sometimes AMDBAR works well
%    for symmetric indefinite matrices too.  AMDBAR tends to be much faster
%    than SYMMMD and tends to return a better ordering.  WARNING: AMDBAR does
%    not drop dense rows and columns in A (they should be ordered last, prior
%    to calling AMDBAR, but this routine does not do that).  A single dense row
%    can cause AMDBAR to take time proportional to n^2 to compute the ordering.
%    If you have dense rows/columns, use SYMAMD or SYMMMD instead, or drop them
%    from your matrix prior to calling this routine.
%
%    See also SYMAMDTREE, COLAMD, COLAMDTREE, COLMMD, SYMMMD, SYMRCM, COLPERM.
%
%    Authors:  
%	Amdbar was written by Timothy A. Davis, Patrick Amestoy, Iain S. Duff,
%	and John K. Reid.  Timothy A. Davis (davis@cise.ufl.edu), University
%	of Florida, wrote the Matlab interface for amdbar.
%
%	************************************************************************
%	* NOTICE:  "The AMD routines (AMDEXA, AMDBAR, AMDHAF, AMDHAT, AMDTRU,
%	* and AMDATR) may be used SOLELY for educational, research, and
%	* benchmarking purposes by non-profit organizations and the U.S.
%	* government.  Commercial and other organizations may make use of the
%	* AMD routines SOLELY for benchmarking purposes only.  The AMD
%	* routines may be modified by or on behalf of the User for such
%	* use but at no time shall the AMD routines or any such modified
%	* version of them become the property of the User.  The AMD routines
%	* are provided without warranty of any kind, either expressed or
%	* implied.  Neither the Authors nor their employers shall be liable
%	* for any direct or consequential loss or damage whatsoever arising
%	* out of the use or misuse of the AMD routines by the User.  The AMD
%	* routines must not be sold.  You may make copies of the AMD routines,
%	* but this NOTICE and the Copyright notice must appear in all copies.
%	* Any other use of the AMD routines requires written permission.
%	* Your use of the AMD routines is an implicit agreement to these
%	* conditions."
%	************************************************************************
%
%    This work was supported by the National Science Foundation, under grants
%    DMS-9504974 and DMS-9803599. AMDBAR is available at
%    http://www.cise.ufl.edu/~davis/amd, and http://www.netlib.org/linalg/amd.

%    Tested under Matlab 5.2.0.3084, using Solaris 2.6.  August 6, 1998.
%    This file is provided so that "help amdbar" prints the above description.

help amdbar
disp ('Warning!  Valid amdbar mexFunction not found.  Using symmmd instead.') ;
p = symmmd (S) ;

