1 package org.djutils.stats.summarizers;
2
3 import java.io.Serializable;
4
5 /**
6 * The Statistic interface defines the methods to implement for each of the statistics classes.
7 * <p>
8 * Copyright (c) 2023-2025 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved. See
9 * for project information <a href="https://simulation.tudelft.nl/" target="_blank"> https://simulation.tudelft.nl</a>. The DSOL
10 * project is distributed under a three-clause BSD-style license, which can be found at
11 * <a href="https://simulation.tudelft.nl/dsol/3.0/license.html" target="_blank">
12 * https://simulation.tudelft.nl/dsol/3.0/license.html</a>. <br>
13 * @author <a href="https://www.tudelft.nl/averbraeck" target="_blank"> Alexander Verbraeck</a>
14 */
15 public interface Statistic extends Serializable
16 {
17 /**
18 * Initialize the statistic.
19 */
20 void initialize();
21
22 /**
23 * Returns the description of the statistic.
24 * @return the description of the statistic
25 */
26 String getDescription();
27
28 /**
29 * Set a new description of the statistic.
30 * @param description the new description of the statistic
31 */
32 void setDescription(String description);
33
34 /**
35 * Return the current number of observations.
36 * @return the number of observations
37 */
38 long getN();
39
40 /**
41 * Return a string representing a line with important statistics values for this statistic, for a textual table with a
42 * monospaced font that can contain multiple statistics.
43 * @return line with most important values of the statistic
44 */
45 String reportLine();
46
47 /**
48 * Return a formatted string with 2 digits precision for a floating point value that fits the number of characters. The
49 * formatter will fall back to scientific notation when the value does not fit with floating point notation.
50 * @param value the value to format
51 * @param numberCharacters the number of characters for the result
52 * @return a string representation with the given number of characters
53 */
54 default String formatFixed(final double value, final int numberCharacters)
55 {
56 if (Double.isNaN(value) || Double.isInfinite(value) || value == 0.0 || Math.abs(value) >= 0.01)
57 {
58 String formatted = String.format("%" + numberCharacters + ".3f", value);
59 if (formatted.length() == numberCharacters)
60 {
61 return formatted;
62 }
63 }
64 return String.format("%" + numberCharacters + ".3e", value);
65 }
66 }