source: trunk/sources/HeuristicLab.Visualization.ChartControlsExtensions/3.3/ChartUtil.cs @ 14156

Last change on this file since 14156 was 14156, checked in by bburlacu, 5 years ago

##2594: Fix bug in scaling when interval is too small to be rounded to multiples of 5 or 10.

File size: 5.2 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 (decimalRank > 0) {
40        if (((aMin % 5).IsAlmost(0) || (aMin % 10).IsAlmost(0)) && !((aMax % 5).IsAlmost(0) || (aMax % 10).IsAlmost(0))) {
41          aMax = Math.Min(aMax + 5 - aMax % 5, aMax + 10 - aMax % 10);
42        } else if (((aMax % 5).IsAlmost(0) || (aMax % 10).IsAlmost(0)) && !((aMin % 5).IsAlmost(0) || (aMin % 10).IsAlmost(0))) {
43          aMin = Math.Max(aMin - aMin % 5, aMin - aMin % 10);
44        }
45      }
46
47      axisMin = aMin;
48      axisMax = aMax;
49      axisInterval = (aMax - aMin) / ticks;
50    }
51
52    /// <summary>
53    /// 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.
54    /// </summary>
55    public static void CalculateOptimalAxisInterval(double min, double max, out double axisMin, out double axisMax, out double axisInterval) {
56      CalculateAxisInterval(min, max, 5, out axisMin, out axisMax, out axisInterval);
57      int bestLsp = int.MaxValue;
58      for (int ticks = 3; ticks <= 5; ++ticks) {
59        double aMin, aMax, aInterval;
60        CalculateAxisInterval(min, max, ticks, out aMin, out aMax, out aInterval);
61        var x = aInterval;
62        int lsp = 0; // position of the least significant fractional digit
63        while (x - Math.Floor(x) > 0) {
64          ++lsp;
65          x *= 10;
66        }
67        if (lsp <= bestLsp) {
68          axisMin = aMin;
69          axisMax = aMax;
70          axisInterval = aInterval;
71          bestLsp = lsp;
72        }
73      }
74    }
75
76    // find the number of decimals needed to represent the value
77    private static int Decimals(this double x) {
78      if (x.IsAlmost(0) || double.IsInfinity(x) || double.IsNaN(x))
79        return 0;
80
81      var v = Math.Abs(x);
82      int d = 1;
83      while (v < 1) {
84        v *= 10;
85        d++;
86      }
87      return d;
88    }
89
90    private static double RoundDown(this double value, int decimalRank) {
91      if (decimalRank > 0) {
92        var floor = (int)Math.Floor(value);
93        var pow = (int)Math.Pow(10, decimalRank);
94        var mod = floor % pow;
95        if (mod < 0) mod += pow;
96        return floor - mod;
97      }
98      return value.Floor(Math.Abs(decimalRank));
99    }
100
101    private static double RoundUp(this double value, int decimalRank) {
102      if (decimalRank > 0) {
103        var ceil = (int)Math.Ceiling(value);
104        var pow = (int)Math.Pow(10, decimalRank);
105        var mod = ceil % pow;
106        if (mod < 0) mod += pow;
107        return ceil - mod + pow;
108      }
109      return value.Ceil(Math.Abs(decimalRank));
110    }
111
112    private static double RoundNearest(this double value, int decimalRank) {
113      var nearestDown = value.RoundDown(decimalRank);
114      var nearestUp = value.RoundUp(decimalRank);
115
116      if (nearestUp - value > value - nearestDown)
117        return nearestDown;
118
119      return nearestUp;
120    }
121
122    // rounds down to the nearest value according to the given number of decimal precision
123    private static double Floor(this double value, int precision) {
124      var n = Math.Pow(10, precision);
125      return Math.Round(Math.Floor(value * n) / n, precision);
126    }
127
128    // rounds up to the nearest value according to the given number of decimal precision
129    private static double Ceil(this double value, int precision) {
130      var n = Math.Pow(10, precision);
131      return Math.Round(Math.Ceiling(value * n) / n, precision);
132    }
133
134    private static bool IsAlmost(this double value, double other, double eps = 1e-12) {
135      return Math.Abs(value - other) < eps;
136    }
137  }
138}
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