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.estimator;
39
40 /**
41 * The StatisticalEstimator interface defines a free energy estimator in the most generic sense.
42 * Implementations should generally perform their estimation during initialization.
43 *
44 * <p>All energy values are typically expressed in units consistent with the software (e.g., kcal/mol).</p>
45 *
46 * @author Michael J. Schnieders
47 * @author Jacob M. Litman
48 * @since 1.0
49 */
50 public interface StatisticalEstimator {
51
52 /**
53 * Gets the free energy difference between each pair of states.
54 *
55 * @return Array of free energy differences between states.
56 */
57 double[] getFreeEnergyDifferences();
58
59 /**
60 * Gets the uncertainty in free energy difference between each pair of states.
61 *
62 * @return Array of uncertainties in the free energy differences.
63 */
64 double[] getFEDifferenceUncertainties();
65
66 /**
67 * Returns the total free energy difference between the first and last state.
68 *
69 * @return Total free energy difference estimate.
70 */
71 double getTotalFreeEnergyDifference();
72
73 /**
74 * Returns the total uncertainty in the computed free energy difference between the first and last state.
75 *
76 * @return Total uncertainty in the free energy difference.
77 */
78 double getTotalFEDifferenceUncertainty();
79
80 /**
81 * Returns the number of windows (BAR, etc), bins (WHAM, etc), or other sub-values used to compute
82 * the total free energy difference.
83 *
84 * @return Total number of windows used to compute the total free energy difference.
85 */
86 int getNumberOfBins();
87
88 /**
89 * Gets the total enthalpy difference between the first and last state.
90 *
91 * @return The enthalpy difference between each pair of states.
92 */
93 double getTotalEnthalpyDifference();
94
95 /**
96 * Gets the enthalpy change between each pair of states.
97 *
98 * @return The enthalpy difference between each pair of states.
99 */
100 double[] getEnthalpyDifferences();
101 }