--- /dev/null
+## Copyright (C) 2002 Etienne Grossmann <etienne@egdn.net>
+##
+## This program is free software; you can redistribute it and/or modify it under
+## the terms of the GNU General Public License as published by the Free Software
+## Foundation; either version 3 of the License, or (at your option) any later
+## version.
+##
+## This program is distributed in the hope that it will be useful, but WITHOUT
+## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+## FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+## details.
+##
+## You should have received a copy of the GNU General Public License along with
+## this program; if not, see <http://www.gnu.org/licenses/>.
+
+## Test whether d2_min() functions correctly
+##
+## Gives a 2-dim function with strange shape ("ff", defined below).
+##
+## Sets a ok variable to 1 in case of success, 0 in case of failure
+##
+## If a variables "verbose" is set, then some comments are output.
+
+1 ;
+
+ok = 0;
+
+if ! exist ("verbose"), verbose = 0; end
+
+if verbose
+ printf ("\n Testing d2_min () on a strange 2-dimensional function\n\n");
+end
+
+P = 2; # Nparams
+noise = 0 ;
+truep = [0;0] ;
+xinit = randn(P,1) ;
+
+if noise, obses = adnois(obses,noise); end
+
+y = nan;
+
+
+function v = ff (x, y)
+ v = x(1)^2 * (1+sin(x(2)*3*pi)^2) + x(2)^2;
+endfunction
+
+
+function [w,dv,d2v] = d2ff (x, y)
+ u = x(1); v = x(2);
+ w = u^2 * (1+sin(v*3*pi)^2) + v^2;
+
+ dv = [2*u * (1+sin(v*3*pi)^2), u^2 * sin(v*2*3*pi) + 2*v ];
+
+ d2v = [2*(1+sin(v*3*pi)^2), 2*u * sin(v*2*3*pi) ;
+ 2*u * sin(v*2*3*pi), u^2 * 2*3*pi* cos(v*2*3*pi) + 2 ];
+ d2v = inv (d2v);
+endfunction
+
+## dt = mytic()
+##
+## Returns the cputime since last call to 'mytic'.
+
+function dt = mytic()
+ persistent last_mytic = 0 ;
+ [t,u,s] = cputime() ;
+ dt = t - last_mytic ;
+ last_mytic = t ;
+endfunction
+
+
+ctl = nan*zeros(1,5); ctl(5) = 1;
+
+if verbose
+ printf ( "Going to call d2_min\n");
+end
+mytic() ;
+[xlev,vlev,nev] = d2_min ("ff", "d2ff", {xinit,y},ctl) ;
+tlev = mytic ();
+
+if verbose,
+ printf("d2_min should find minv = 0 (plus a little error)\n");
+ printf(["d2_min : niter=%-4d nev=%-4d nparams=%-4d\n",...
+ " time=%-8.3g errx=%-8.3g minv=%-8.3g\n"],...
+ nev([2,1]), P, tlev, max (abs (xlev-truep)), vlev);
+end
+
+ok = 1;
+
+if max (abs(xlev-truep )) > sqrt (eps),
+ if verbose
+ printf ( "Error is too big : %-8.3g\n", max (abs (xlev-truep)));
+ end
+ ok = 0;
+end
+
+if verbose && ok
+ printf ( "All tests ok\n");
+end
+
+
+