source: branches/HeuristicLab.DataImporter/HeuristicLab.DataImporter.Command/ChangeDataset/DeleteColumnsWithTooFewValuesCommand.cs @ 6212

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;
using HeuristicLab.DataImporter.Data;
using HeuristicLab.DataImporter.Data.CommandBase;
using HeuristicLab.DataImporter.Data.Model;
using HeuristicLab.DataImporter.Command.View;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;

namespace HeuristicLab.DataImporter.Command {
  [StorableClass]
  [ViewableCommandInfoAttribute("Delete Columns with too few Values", 1, ColumnGroupState.Active, "ColumnGroup Commands",
   Position = 14, OptionsView = typeof(ThresholdCommandView))]
  public class DeleteColumnsWithTooFewValuesCommand : ColumnGroupCommandBase {
    private SortedDictionary<int, ColumnBase> deletedColumns;
    private ICollection<int> oldSortedColumnIndices;
    private DeleteColumnsWithTooFewValuesCommand()
      : base(null, string.Empty) {
      deletedColumns = new SortedDictionary<int, ColumnBase>();
    }

    public DeleteColumnsWithTooFewValuesCommand(DataSet dataSet, string columnGroupName)
      : base(dataSet, columnGroupName) {
      deletedColumns = new SortedDictionary<int, ColumnBase>();
    }

    [Storable]
    private double threshold;
    public double Threshold {
      get { return this.threshold; }
      set { this.threshold = value; }
    }

    public override string Description {
      get { return "Delete Columns with too few values"; }
    }

    public override void Execute() {
      base.Execute();
      ColumnBase column;
      for (int i = 0; i < ColumnGroup.Columns.Count(); i++) {
        column = ColumnGroup.GetColumn(i);
        if ((1 - ((double)column.NullValuesCount) / column.TotalValuesCount) < threshold)
          deletedColumns.Add(i, column);
      }
      oldSortedColumnIndices = new List<int>(ColumnGroup.SortedColumnIndexes);
      foreach (ColumnBase col in deletedColumns.Values)
        ColumnGroup.RemoveColumn(col);
      ColumnGroup.FireChanged();
      ColumnGroup = null;
    }

    public override void UndoExecute() {
      base.UndoExecute();
      foreach (KeyValuePair<int, ColumnBase> pair in deletedColumns)
        ColumnGroup.InsertColumn(pair.Key, pair.Value);
      ColumnGroup.SortedColumnIndexes = oldSortedColumnIndices;
      oldSortedColumnIndices = null;
      deletedColumns.Clear();
      ColumnGroup.FireChanged();
      ColumnGroup = null;
    }
  }
}