source: trunk/sources/HeuristicLab.Analysis.Statistics.Views/3.3/SampleSizeInfluenceView.cs @ 12599

#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2015 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
 *
 * This file is part of HeuristicLab.
 *
 * HeuristicLab is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * HeuristicLab is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
 */
#endregion

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;
using System.Windows.Forms.DataVisualization.Charting;
using HeuristicLab.Collections;
using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Data;
using HeuristicLab.MainForm;
using HeuristicLab.MainForm.WindowsForms;
using HeuristicLab.Optimization;
using HeuristicLab.PluginInfrastructure;

namespace HeuristicLab.Analysis.Statistics.Views {
  [View("Sample Size Influence", "HeuristicLab.Analysis.Statistics.Views.InfoResources.SampleSizeInfluenceInfo.rtf")]
  [Content(typeof(RunCollection), false)]
  public partial class SampleSizeInfluenceView : AsynchronousContentView {
    private enum AxisDimension { Color = 0 }
    private const string BoxPlotSeriesName = "BoxPlotSeries";
    private const string BoxPlotChartAreaName = "BoxPlotChartArea";
    private const string delimiter = ";";

    private bool suppressUpdates = false;
    private string yAxisValue;
    private Dictionary<int, Dictionary<object, double>> categoricalMapping;
    private SortedDictionary<double, Series> seriesCache;

    public SampleSizeInfluenceView() {
      InitializeComponent();
      categoricalMapping = new Dictionary<int, Dictionary<object, double>>();
      seriesCache = new SortedDictionary<double, Series>();
      chart.ChartAreas[0].Visible = false;
      chart.Series.Clear();
      chart.ChartAreas.Add(BoxPlotChartAreaName);
      chart.CustomizeAllChartAreas();
      chart.ChartAreas[BoxPlotChartAreaName].Axes.ToList().ForEach(x => { x.ScaleView.Zoomable = true; x.ScaleView.MinSize = 0; });
      chart.ChartAreas[BoxPlotChartAreaName].CursorX.Interval = 0.5;
      chart.ChartAreas[BoxPlotChartAreaName].CursorY.Interval = 1e-5;
    }

    public new RunCollection Content {
      get { return (RunCollection)base.Content; }
      set { base.Content = value; }
    }
    public IStringConvertibleMatrix Matrix {
      get { return this.Content; }
    }

    #region RunCollection and Run events
    protected override void RegisterContentEvents() {
      base.RegisterContentEvents();
      Content.ColumnNamesChanged += new EventHandler(Content_ColumnNamesChanged);
      Content.ItemsAdded += new HeuristicLab.Collections.CollectionItemsChangedEventHandler<IRun>(Content_ItemsAdded);
      Content.ItemsRemoved += new HeuristicLab.Collections.CollectionItemsChangedEventHandler<IRun>(Content_ItemsRemoved);
      Content.CollectionReset += new HeuristicLab.Collections.CollectionItemsChangedEventHandler<IRun>(Content_CollectionReset);
      Content.UpdateOfRunsInProgressChanged += new EventHandler(Content_UpdateOfRunsInProgressChanged);
      Content.OptimizerNameChanged += new EventHandler(Content_AlgorithmNameChanged);
      RegisterRunEvents(Content);
    }
    protected override void DeregisterContentEvents() {
      base.DeregisterContentEvents();
      Content.ColumnNamesChanged -= new EventHandler(Content_ColumnNamesChanged);
      Content.ItemsAdded -= new HeuristicLab.Collections.CollectionItemsChangedEventHandler<IRun>(Content_ItemsAdded);
      Content.ItemsRemoved -= new HeuristicLab.Collections.CollectionItemsChangedEventHandler<IRun>(Content_ItemsRemoved);
      Content.CollectionReset -= new HeuristicLab.Collections.CollectionItemsChangedEventHandler<IRun>(Content_CollectionReset);
      Content.UpdateOfRunsInProgressChanged -= new EventHandler(Content_UpdateOfRunsInProgressChanged);
      Content.OptimizerNameChanged -= new EventHandler(Content_AlgorithmNameChanged);
      DeregisterRunEvents(Content);
    }

    protected virtual void RegisterRunEvents(IEnumerable<IRun> runs) {
      foreach (IRun run in runs) {
        RegisterRunParametersEvents(run);
        RegisterRunResultsEvents(run);
      }
    }

    protected virtual void DeregisterRunEvents(IEnumerable<IRun> runs) {
      foreach (IRun run in runs) {
        DeregisterRunParametersEvents(run);
        DeregisterRunResultsEvents(run);
      }
    }

    private void RegisterRunParametersEvents(IRun run) {
      IObservableDictionary<string, IItem> dict = run.Parameters;
      dict.ItemsAdded += run_Changed;
      dict.ItemsRemoved += run_Changed;
      dict.ItemsReplaced += run_Changed;
      dict.CollectionReset += run_Changed;
    }

    private void RegisterRunResultsEvents(IRun run) {
      IObservableDictionary<string, IItem> dict = run.Results;
      dict.ItemsAdded += run_Changed;
      dict.ItemsRemoved += run_Changed;
      dict.ItemsReplaced += run_Changed;
      dict.CollectionReset += run_Changed;
    }

    private void DeregisterRunParametersEvents(IRun run) {
      IObservableDictionary<string, IItem> dict = run.Parameters;
      dict.ItemsAdded -= run_Changed;
      dict.ItemsRemoved -= run_Changed;
      dict.ItemsReplaced -= run_Changed;
      dict.CollectionReset -= run_Changed;
    }

    private void DeregisterRunResultsEvents(IRun run) {
      IObservableDictionary<string, IItem> dict = run.Results;
      dict.ItemsAdded -= run_Changed;
      dict.ItemsRemoved -= run_Changed;
      dict.ItemsReplaced -= run_Changed;
      dict.CollectionReset -= run_Changed;
    }

    private void Content_CollectionReset(object sender, CollectionItemsChangedEventArgs<IRun> e) {
      DeregisterRunEvents(e.OldItems);
      RegisterRunEvents(e.Items);
      if (!suppressUpdates) UpdateAll();
    }
    private void Content_ItemsRemoved(object sender, CollectionItemsChangedEventArgs<IRun> e) {
      DeregisterRunEvents(e.Items);
      if (!suppressUpdates) UpdateComboBoxes();
    }
    private void Content_ItemsAdded(object sender, CollectionItemsChangedEventArgs<IRun> e) {
      RegisterRunEvents(e.Items);
      if (!suppressUpdates) UpdateComboBoxes();
    }
    private void Content_UpdateOfRunsInProgressChanged(object sender, EventArgs e) {
      if (InvokeRequired)
        Invoke(new EventHandler(Content_UpdateOfRunsInProgressChanged), sender, e);
      else {
        suppressUpdates = Content.UpdateOfRunsInProgress;
        if (!suppressUpdates) UpdateAll();
      }
    }
    private void Content_ColumnNamesChanged(object sender, EventArgs e) {
      if (InvokeRequired)
        Invoke(new EventHandler(Content_ColumnNamesChanged), sender, e);
      else {
        if (!suppressUpdates) UpdateComboBoxes();
      }
    }
    private void run_Changed(object sender, EventArgs e) {
      if (InvokeRequired)
        this.Invoke(new EventHandler(run_Changed), sender, e);
      else if (!suppressUpdates) UpdateDataPoints();
    }

    private void Content_AlgorithmNameChanged(object sender, EventArgs e) {
      if (InvokeRequired)
        Invoke(new EventHandler(Content_AlgorithmNameChanged), sender, e);
      else if (!suppressUpdates) UpdateCaption();
    }
    #endregion

    #region update comboboxes, datapoints, runs
    protected override void OnContentChanged() {
      base.OnContentChanged();
      UpdateAll();
    }

    private void UpdateAll() {
      this.categoricalMapping.Clear();
      UpdateComboBoxes();
      UpdateDataPoints();
      UpdateCaption();
    }

    private void UpdateCaption() {
      Caption = Content != null ? Content.OptimizerName + " Sample Size Influence" : ViewAttribute.GetViewName(GetType());
    }

    private void UpdateSampleSizes(bool forceUpdate = false) {
      string selectedYAxis = (string)this.yAxisComboBox.SelectedItem;

      if (selectedYAxis != null && (xAxisTextBox.Text.Trim() == string.Empty || forceUpdate)) {
        xAxisTextBox.Clear();
        List<double> values = new List<double>();
        foreach (IRun run in Content.Where(x => x.Visible)) {
          double? cv = GetValue(run, selectedYAxis);
          if (cv.HasValue) {
            values.Add(cv.Value);
          }
        }

        if (values.Any()) {
          if (hypergeometricCheckBox.Checked) {
            xAxisTextBox.Text += ((int)(values.Count() / 16)) + delimiter + " ";
            xAxisTextBox.Text += ((int)(values.Count() / 8)) + delimiter + " ";
            xAxisTextBox.Text += (int)(values.Count() / 4);
          } else {
            xAxisTextBox.Text += ((int)(values.Count() / 4)) + delimiter + " ";
            xAxisTextBox.Text += ((int)(values.Count() / 2)) + delimiter + " ";
            xAxisTextBox.Text += ((int)(values.Count() / 4 * 3)) + delimiter + " ";
            xAxisTextBox.Text += (int)(values.Count());
          }
        }
      }
    }

    private void UpdateComboBoxes() {
      string selectedYAxis = (string)this.yAxisComboBox.SelectedItem;
      this.xAxisTextBox.Text = string.Empty;
      this.yAxisComboBox.Items.Clear();
      if (Content != null) {
        string[] additionalAxisDimension = Enum.GetNames(typeof(AxisDimension));
        UpdateSampleSizes();
        this.yAxisComboBox.Items.AddRange(additionalAxisDimension);
        this.yAxisComboBox.Items.AddRange(Matrix.ColumnNames.ToArray());

        if (selectedYAxis != null && yAxisComboBox.Items.Contains(selectedYAxis)) {
          yAxisComboBox.SelectedItem = selectedYAxis;
          UpdateDataPoints();
        }
      }
    }

    private void UpdateDataPoints() {
      this.chart.Series.Clear();
      this.seriesCache.Clear();
      if (Content != null) {
        var usableRuns = Content.Where(r => r.Visible).ToList();
        List<int> groupSizes = ParseGroupSizesFromText(xAxisTextBox.Text);

        if (hypergeometricCheckBox.Checked) {
          CalculateGroupsHypergeometric(usableRuns, groupSizes);
        } else {
          CalculateGroups(usableRuns, groupSizes);
        }

        foreach (Series s in this.seriesCache.Values)
          this.chart.Series.Add(s);

        UpdateStatistics();
        if (seriesCache.Count > 0) {
          Series boxPlotSeries = CreateBoxPlotSeries();
          this.chart.Series.Add(boxPlotSeries);
        }

        UpdateAxisLabels();
        if (groupSizes.Any())
          AddSampleSizeText();
      } else {
        sampleSizeTextBox.Text = string.Empty;
      }
      UpdateNoRunsVisibleLabel();
    }

    private void CalculateGroups(List<IRun> usableRuns, List<int> groupSizes) {
      Random rand = new Random();

      foreach (int gs in groupSizes) {
        int idx = gs;
        List<IRun> runGroup = new List<IRun>();
        if (idx > usableRuns.Count()) {
          idx = usableRuns.Count();
        }

        for (int i = 0; i < idx; i++) {
          int r = rand.Next(usableRuns.Count());
          runGroup.Add(usableRuns[r]);
        }
        runGroup.ForEach(x => AddDataPoint(x, idx));
      }
    }

    private void CalculateGroupsHypergeometric(List<IRun> usableRuns, List<int> groupSizes) {
      Random rand = new Random();
      var runs = new List<IRun>(usableRuns);

      foreach (int gs in groupSizes) {
        int idx = gs;
        List<IRun> runGroup = new List<IRun>();
        if (idx > runs.Count()) {
          idx = runs.Count();
        }

        for (int i = 0; i < idx; i++) {
          int r = rand.Next(runs.Count());
          runGroup.Add(runs[r]);
          runs.Remove(runs[r]);
        }
        runGroup.ForEach(x => AddDataPoint(x, idx));
      }
    }

    private void AddSampleSizeText() {
      sampleSizeTextBox.Text = string.Empty;
      var usableRuns = Content.Where(r => r.Visible).ToList();

      if (!yAxisComboBox.DroppedDown)
        this.yAxisValue = (string)yAxisComboBox.SelectedItem;

      List<double?> yValue = usableRuns.Select(x => GetValue(x, this.yAxisValue)).ToList();
      if (yValue.Any(x => !x.HasValue)) return;

      double estimatedSampleSize = SampleSizeDetermination.DetermineSampleSizeByEstimatingMean(yValue.Select(x => x.Value).ToArray());
      sampleSizeTextBox.Text = estimatedSampleSize.ToString();
    }

    private List<int> ParseGroupSizesFromText(string groupsText, bool verbose = true) {
      string[] gs = groupsText.Split(delimiter.ToCharArray());
      List<int> vals = new List<int>();

      foreach (string s in gs) {
        string ns = s.Trim();

        if (ns != string.Empty) {
          int v = 0;
          try {
            v = int.Parse(ns);
            vals.Add(v);
          } catch (Exception ex) {
            if (verbose) {
              ErrorHandling.ShowErrorDialog("Can't parse group sizes. Please only use numbers seperated by a " + delimiter + ". ", ex);
            }
          }
        }
      }
      return vals;
    }

    private void UpdateStatistics() {
      DoubleMatrix matrix = new DoubleMatrix(11, seriesCache.Count);
      matrix.SortableView = false;
      List<string> columnNames = new List<string>();
      foreach (Series series in seriesCache.Values) {
        DataPoint datapoint = series.Points.FirstOrDefault();
        if (datapoint != null) {
          IRun run = (IRun)datapoint.Tag;
          string selectedAxis = xAxisTextBox.Text;
          IItem value = null;

          if (Enum.IsDefined(typeof(AxisDimension), selectedAxis)) {
            AxisDimension axisDimension = (AxisDimension)Enum.Parse(typeof(AxisDimension), selectedAxis);
            switch (axisDimension) {
              case AxisDimension.Color: value = new StringValue(run.Color.ToString());
                break;
            }
          }

          string columnName = series.Name;
          columnNames.Add(columnName);
        }
      }
      matrix.ColumnNames = columnNames;
      matrix.RowNames = new string[] { "Count", "Minimum", "Maximum", "Average", "Median", "Standard Deviation", "Variance", "25th Percentile", "75th Percentile", "Lower Confidence Int.", "Upper Confidence Int." };

      for (int i = 0; i < seriesCache.Count; i++) {
        Series series = seriesCache.ElementAt(i).Value;
        double[] seriesValues = series.Points.Select(p => p.YValues[0]).OrderBy(d => d).ToArray();
        Tuple<double, double> confIntervals = seriesValues.ConfidenceIntervals(0.95);
        matrix[0, i] = seriesValues.Length;
        matrix[1, i] = seriesValues.Min();
        matrix[2, i] = seriesValues.Max();
        matrix[3, i] = seriesValues.Average();
        matrix[4, i] = seriesValues.Median();
        matrix[5, i] = seriesValues.StandardDeviation();
        matrix[6, i] = seriesValues.Variance();
        matrix[7, i] = seriesValues.Percentile(0.25);
        matrix[8, i] = seriesValues.Percentile(0.75);
        matrix[9, i] = confIntervals.Item1;
        matrix[10, i] = confIntervals.Item2;
      }
      statisticsMatrixView.Content = matrix;
    }

    private Series CreateBoxPlotSeries() {
      Series boxPlotSeries = new Series(BoxPlotSeriesName);
      string seriesNames = string.Concat(seriesCache.Keys.Select(x => x.ToString() + ";").ToArray());
      seriesNames = seriesNames.Remove(seriesNames.Length - 1); //delete last ; from string

      boxPlotSeries.ChartArea = BoxPlotChartAreaName;
      boxPlotSeries.ChartType = SeriesChartType.BoxPlot;
      boxPlotSeries["BoxPlotSeries"] = seriesNames;
      boxPlotSeries["BoxPlotShowUnusualValues"] = "true";
      boxPlotSeries["PointWidth"] = "0.4";
      boxPlotSeries.BackGradientStyle = System.Windows.Forms.DataVisualization.Charting.GradientStyle.VerticalCenter;
      boxPlotSeries.BackSecondaryColor = System.Drawing.Color.FromArgb(130, 224, 64, 10);
      boxPlotSeries.BorderColor = System.Drawing.Color.FromArgb(64, 64, 64);
      boxPlotSeries.Color = System.Drawing.Color.FromArgb(224, 64, 10);

      return boxPlotSeries;
    }

    private void AddDataPoint(IRun run, int idx) {
      double xValue;
      double? yValue;


      if (!yAxisComboBox.DroppedDown)
        this.yAxisValue = (string)yAxisComboBox.SelectedItem;

      xValue = idx;
      yValue = GetValue(run, this.yAxisValue);

      if (yValue.HasValue) {
        if (!this.seriesCache.ContainsKey(xValue))
          seriesCache[xValue] = new Series(xValue.ToString());

        Series series = seriesCache[xValue];
        DataPoint point = new DataPoint(xValue, yValue.Value);
        point.Tag = run;
        series.Points.Add(point);
      }
    }
    #endregion

    #region get values from run
    private double? GetValue(IRun run, string columnName) {
      if (run == null || string.IsNullOrEmpty(columnName))
        return null;

      if (Enum.IsDefined(typeof(AxisDimension), columnName)) {
        AxisDimension axisDimension = (AxisDimension)Enum.Parse(typeof(AxisDimension), columnName);
        return GetValue(run, axisDimension);
      } else {
        int columnIndex = Matrix.ColumnNames.ToList().IndexOf(columnName);
        IItem value = Content.GetValue(run, columnIndex);
        if (value == null)
          return null;

        DoubleValue doubleValue = value as DoubleValue;
        IntValue intValue = value as IntValue;
        TimeSpanValue timeSpanValue = value as TimeSpanValue;
        double? ret = null;
        if (doubleValue != null) {
          if (!double.IsNaN(doubleValue.Value) && !double.IsInfinity(doubleValue.Value))
            ret = doubleValue.Value;
        } else if (intValue != null)
          ret = intValue.Value;
        else if (timeSpanValue != null) {
          ret = timeSpanValue.Value.TotalSeconds;
        } else
          ret = GetCategoricalValue(columnIndex, value.ToString());

        return ret;
      }
    }
    private double GetCategoricalValue(int dimension, string value) {
      if (!this.categoricalMapping.ContainsKey(dimension)) {
        this.categoricalMapping[dimension] = new Dictionary<object, double>();
        var orderedCategories = Content.Where(r => r.Visible && Content.GetValue(r, dimension) != null).Select(r => Content.GetValue(r, dimension).ToString())
                                          .Distinct().OrderBy(x => x, new NaturalStringComparer());
        int count = 1;
        foreach (var category in orderedCategories) {
          this.categoricalMapping[dimension].Add(category, count);
          count++;
        }
      }
      return this.categoricalMapping[dimension][value];
    }
    private double GetValue(IRun run, AxisDimension axisDimension) {
      double value = double.NaN;
      switch (axisDimension) {
        case AxisDimension.Color: {
            value = GetCategoricalValue(-1, run.Color.ToString());
            break;
          }
        default: {
            throw new ArgumentException("No handling strategy for " + axisDimension.ToString() + " is defined.");
          }
      }
      return value;
    }
    #endregion

    #region GUI events
    private void UpdateNoRunsVisibleLabel() {
      if (this.chart.Series.Count > 0) {
        noRunsLabel.Visible = false;
        showStatisticsCheckBox.Enabled = true;
        splitContainer.Panel2Collapsed = !showStatisticsCheckBox.Checked;
      } else {
        noRunsLabel.Visible = true;
        showStatisticsCheckBox.Enabled = false;
        splitContainer.Panel2Collapsed = true;
      }
    }

    private void RecalculateButton_Click(object sender, EventArgs e) {
      UpdateDataPoints();
    }

    private void hypergeometricCheckBox_CheckedChanged(object sender, EventArgs e) {
      UpdateSampleSizes(true);
      UpdateDataPoints();
    }

    private void AxisComboBox_SelectedIndexChanged(object sender, EventArgs e) {
      UpdateSampleSizes();
      UpdateDataPoints();
    }
    private void UpdateAxisLabels() {
      Axis xAxis = this.chart.ChartAreas[BoxPlotChartAreaName].AxisX;
      Axis yAxis = this.chart.ChartAreas[BoxPlotChartAreaName].AxisY;
      int axisDimensionCount = Enum.GetNames(typeof(AxisDimension)).Count();

      SetCustomAxisLabels(xAxis, -1);
      SetCustomAxisLabels(yAxis, yAxisComboBox.SelectedIndex - axisDimensionCount);

      xAxis.Title = "Group Size";
      if (yAxisComboBox.SelectedItem != null)
        yAxis.Title = yAxisComboBox.SelectedItem.ToString();
    }

    private void chart_AxisViewChanged(object sender, System.Windows.Forms.DataVisualization.Charting.ViewEventArgs e) {
      this.UpdateAxisLabels();
    }

    private void SetCustomAxisLabels(Axis axis, int dimension) {
      axis.CustomLabels.Clear();
      if (categoricalMapping.ContainsKey(dimension)) {
        int position = 1;
        foreach (var pair in categoricalMapping[dimension].Where(x => seriesCache.ContainsKey(x.Value))) {
          string labelText = pair.Key.ToString();
          CustomLabel label = new CustomLabel();
          label.ToolTip = labelText;
          if (labelText.Length > 25)
            labelText = labelText.Substring(0, 25) + " ... ";
          label.Text = labelText;
          label.GridTicks = GridTickTypes.TickMark;
          label.FromPosition = position - 0.5;
          label.ToPosition = position + 0.5;
          axis.CustomLabels.Add(label);
          position++;
        }
      } else if (dimension > 0 && Content.GetValue(0, dimension) is TimeSpanValue) {
        this.chart.ChartAreas[0].RecalculateAxesScale();
        Axis correspondingAxis = this.chart.ChartAreas[0].Axes.Where(x => x.Name == axis.Name).SingleOrDefault();
        if (correspondingAxis == null)
          correspondingAxis = axis;
        for (double i = correspondingAxis.Minimum; i <= correspondingAxis.Maximum; i += correspondingAxis.LabelStyle.Interval) {
          TimeSpan time = TimeSpan.FromSeconds(i);
          string x = string.Format("{0:00}:{1:00}:{2:00}", (int)time.Hours, time.Minutes, time.Seconds);
          axis.CustomLabels.Add(i - correspondingAxis.LabelStyle.Interval / 2, i + correspondingAxis.LabelStyle.Interval / 2, x);
        }
      } else if (chart.ChartAreas[BoxPlotChartAreaName].AxisX == axis) {
        double position = 1.0;
        foreach (Series series in chart.Series) {
          if (series.Name != BoxPlotSeriesName) {
            string labelText = series.Points[0].XValue.ToString();
            CustomLabel label = new CustomLabel();
            label.FromPosition = position - 0.5;
            label.ToPosition = position + 0.5;
            label.GridTicks = GridTickTypes.TickMark;
            label.Text = labelText;
            axis.CustomLabels.Add(label);
            position++;
          }
        }
      }
    }

    private void chart_MouseMove(object sender, MouseEventArgs e) {
      string newTooltipText = string.Empty;
      string oldTooltipText;
      HitTestResult h = this.chart.HitTest(e.X, e.Y);
      if (h.ChartElementType == ChartElementType.AxisLabels) {
        newTooltipText = ((CustomLabel)h.Object).ToolTip;
      }

      oldTooltipText = this.tooltip.GetToolTip(chart);
      if (newTooltipText != oldTooltipText)
        this.tooltip.SetToolTip(chart, newTooltipText);
    }
    #endregion

    private void showStatisticsCheckBox_CheckedChanged(object sender, EventArgs e) {
      splitContainer.Panel2Collapsed = !showStatisticsCheckBox.Checked;
    }

    private void defineSampleSizeButton_Click(object sender, EventArgs e) {
      int min = 0, max = 0, step = 1;
      var groupSizes = ParseGroupSizesFromText(xAxisTextBox.Text);
      if (groupSizes.Count() > 0) {
        min = groupSizes.Min();
        max = groupSizes.Max();
      }

      using (var dialog = new DefineArithmeticProgressionDialog(true, min, max, step)) {
        if (dialog.ShowDialog(this) == DialogResult.OK) {
          var values = dialog.Values;
          string newVals = "";
          foreach (int v in values) {
            newVals += v + delimiter + " ";
          }
          xAxisTextBox.Text = newVals;
        }
      }
    }

    private void xAxisTextBox_TextChanged(object sender, EventArgs e) {
      var result = ParseGroupSizesFromText(xAxisTextBox.Text, false);

      if (seriesCache.Count() == result.Count()) {
        bool changed = false;
        int i = 0;
        foreach (var gs in seriesCache.Keys) {
          if (((int)gs) != result[i]) {
            changed = true;
            break;
          }
          i++;
        }

        if (changed) {
          UpdateDataPoints();
        }
      } else {
        UpdateDataPoints();
      }
    }
  }
}