source: trunk/sources/HeuristicLab.Visualization.ChartControlsExtensions/3.3/ChartUtil.cs @ 14160

Last change on this file since 14160 was 14160, checked in by bburlacu, 5 years ago

#2594: Fix very small omission.

File size: 5.3 KB
Line 
1#region License Information
2
3/* HeuristicLab
4 * Copyright (C) 2002-2016 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
5 *
6 * This file is part of HeuristicLab.
7 *
8 * HeuristicLab is free software: you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation, either version 3 of the License, or
11 * (at your option) any later version.
12 *
13 * HeuristicLab is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
20 */
21
22#endregion
23
24using System;
25
26namespace HeuristicLab.Visualization.ChartControlsExtensions {
27  public static class ChartUtil {
28    public static void CalculateAxisInterval(double min, double max, int ticks, out double axisMin, out double axisMax, out double axisInterval) {
29      if (double.IsInfinity(min) || double.IsNaN(min) || double.IsInfinity(max) || double.IsNaN(max) || (min >= max))
30        throw new ArgumentOutOfRangeException("Invalid range provided.");
31
32      var range = max - min;
33      var dRange = (int)Math.Round(Math.Log10(range));
34      int decimalRank = dRange - 1;
35      var aMin = min.RoundDown(decimalRank);
36      var aMax = max.RoundUp(decimalRank);
37
38      // if one of the interval ends is a multiple of 5 or 10, change the other interval end to be a multiple as well
39      if ((aMin.Mod(5).IsAlmost(0) || aMin.Mod(10).IsAlmost(0)) && Math.Abs(aMax) >= 5 && !(aMax.Mod(5).IsAlmost(0) || aMax.Mod(10).IsAlmost(0))) {
40        aMax = Math.Min(aMax + 5 - aMax.Mod(5), aMax + 10 - aMax.Mod(10));
41      } else if ((aMax.Mod(5).IsAlmost(0) || aMax.Mod(10).IsAlmost(0)) && Math.Abs(aMin) >= 5 && !(aMin.Mod(5).IsAlmost(0) || aMin.Mod(10).IsAlmost(0))) {
42        aMin = Math.Max(aMin - aMin.Mod(5), aMin - aMin.Mod(10));
43      }
44
45      axisMin = aMin;
46      axisMax = aMax;
47      axisInterval = (aMax - aMin) / ticks;
48    }
49
50    /// <summary>
51    /// Tries to find an axis interval with as few fractional digits as possible (because it looks nicer).  we only try between 3 and 5 ticks (inclusive) because it wouldn't make sense to exceed this interval.
52    /// </summary>
53    public static void CalculateOptimalAxisInterval(double min, double max, out double axisMin, out double axisMax, out double axisInterval) {
54      CalculateAxisInterval(min, max, 5, out axisMin, out axisMax, out axisInterval);
55      int bestLsp = int.MaxValue;
56      for (int ticks = 3; ticks <= 5; ++ticks) {
57        double aMin, aMax, aInterval;
58        CalculateAxisInterval(min, max, ticks, out aMin, out aMax, out aInterval);
59        var x = aInterval;
60        int lsp = 0; // position of the least significant fractional digit
61        while (x - Math.Floor(x) > 0) {
62          ++lsp;
63          x *= 10;
64        }
65        if (lsp <= bestLsp) {
66          axisMin = aMin;
67          axisMax = aMax;
68          axisInterval = aInterval;
69          bestLsp = lsp;
70        }
71      }
72    }
73
74    // find the number of decimals needed to represent the value
75    private static int Decimals(this double x) {
76      if (x.IsAlmost(0) || double.IsInfinity(x) || double.IsNaN(x))
77        return 0;
78
79      var v = Math.Abs(x);
80      int d = 1;
81      while (v < 1) {
82        v *= 10;
83        d++;
84      }
85      return d;
86    }
87
88    private static double RoundDown(this double value, int decimalRank) {
89      if (decimalRank > 0) {
90        var floor = (int)Math.Floor(value);
91        var pow = (int)Math.Pow(10, decimalRank);
92        var mod = Mod(floor, pow);
93        return floor - mod;
94      }
95      return value.Floor(Math.Abs(decimalRank));
96    }
97
98    private static double RoundUp(this double value, int decimalRank) {
99      if (decimalRank > 0) {
100        var ceil = (int)Math.Ceiling(value);
101        var pow = (int)Math.Pow(10, decimalRank);
102        var mod = Mod(ceil, pow);
103        return ceil - mod + pow;
104      }
105      return value.Ceil(Math.Abs(decimalRank));
106    }
107
108    private static double RoundNearest(this double value, int decimalRank) {
109      var nearestDown = value.RoundDown(decimalRank);
110      var nearestUp = value.RoundUp(decimalRank);
111
112      if (nearestUp - value > value - nearestDown)
113        return nearestDown;
114
115      return nearestUp;
116    }
117
118    // rounds down to the nearest value according to the given number of decimal precision
119    private static double Floor(this double value, int precision) {
120      var n = Math.Pow(10, precision);
121      return Math.Round(Math.Floor(value * n) / n, precision);
122    }
123
124    // rounds up to the nearest value according to the given number of decimal precision
125    private static double Ceil(this double value, int precision) {
126      var n = Math.Pow(10, precision);
127      return Math.Round(Math.Ceiling(value * n) / n, precision);
128    }
129
130    private static bool IsAlmost(this double value, double other, double eps = 1e-12) {
131      return Math.Abs(value - other) < eps;
132    }
133
134    private static double Mod(this double a, double b) {
135      return a - b * Math.Floor(a / b);
136    }
137  }
138}
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