1 // ******************************************************************************
2 //
3 // Title: Force Field X.
4 // Description: Force Field X - Software for Molecular Biophysics.
5 // Copyright: Copyright (c) Michael J. Schnieders 2001-2025.
6 //
7 // This file is part of Force Field X.
8 //
9 // Force Field X is free software; you can redistribute it and/or modify it
10 // under the terms of the GNU General Public License version 3 as published by
11 // the Free Software Foundation.
12 //
13 // Force Field X is distributed in the hope that it will be useful, but WITHOUT
14 // ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
15 // FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
16 // details.
17 //
18 // You should have received a copy of the GNU General Public License along with
19 // Force Field X; if not, write to the Free Software Foundation, Inc., 59 Temple
20 // Place, Suite 330, Boston, MA 02111-1307 USA
21 //
22 // Linking this library statically or dynamically with other modules is making a
23 // combined work based on this library. Thus, the terms and conditions of the
24 // GNU General Public License cover the whole combination.
25 //
26 // As a special exception, the copyright holders of this library give you
27 // permission to link this library with independent modules to produce an
28 // executable, regardless of the license terms of these independent modules, and
29 // to copy and distribute the resulting executable under terms of your choice,
30 // provided that you also meet, for each linked independent module, the terms
31 // and conditions of the license of that module. An independent module is a
32 // module which is not derived from or based on this library. If you modify this
33 // library, you may extend this exception to your version of the library, but
34 // you are not obligated to do so. If you do not wish to do so, delete this
35 // exception statement from your version.
36 //
37 // ******************************************************************************
38 package ffx.numerics.optimization;
39
40 import ffx.numerics.optimization.LineSearch.LineSearchResult;
41
42 /**
43 * This interface allows the optimizer to notify registered instances of successful steps. Currently
44 * only one listener is supported.
45 *
46 * @author Michael J. Schnieders
47 * @since 1.0
48 */
49 public interface OptimizationListener {
50
51 /**
52 * This method is called by the optimizer after each step.
53 *
54 * <p>It can be used to log status messages, update the user interface, or gracefully terminate
55 * the optimizer.
56 *
57 * @param iter Number of iterations.
58 * @param nBFGS Number of L-BFGS correction vectors.
59 * @param nFunctionEvals Number of function evaluations.
60 * @param gradientRMS RMS gradient at current solution.
61 * @param coordinateRMS RMS coordinate change at current solution.
62 * @param f Function value at current solution.
63 * @param df Change in the function value compared to the previous solution.
64 * @param angle Current angle between gradient and search direction.
65 * @param info Result of the line search (null at iteration == 0).
66 * @return A return value of false will terminate the optimization.
67 * @since 1.0
68 */
69 boolean optimizationUpdate(int iter, int nBFGS, int nFunctionEvals, double gradientRMS,
70 double coordinateRMS, double f, double df, double angle, LineSearchResult info);
71 }