source: branches/DataPreprocessing/HeuristicLab.DataPreprocessing/3.3/Implementations/ManipulationLogic.cs @ 10611

#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2013 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 HeuristicLab.Data;

namespace HeuristicLab.DataPreprocessing {
  public class ManipulationLogic : IManipulationLogic {
    private ITransactionalPreprocessingData preprocessingData;
    private IStatisticsLogic statisticInfo;
    private ISearchLogic searchLogic;

    public ManipulationLogic(ITransactionalPreprocessingData _prepocessingData, ISearchLogic theSearchLogic, IStatisticsLogic theStatisticsLogic) {
      preprocessingData = _prepocessingData;
      searchLogic = theSearchLogic;
      statisticInfo = theStatisticsLogic;
    }

    public void ReplaceIndicesByValue<T>(int columnIndex, IEnumerable<int> rowIndices, T value) {
      foreach (int index in rowIndices) {
        preprocessingData.SetCell<T>(columnIndex, index, value);
      }
    }

    public void ReplaceIndicesByAverageValue(Dictionary<int, List<int>> cells) {
      preprocessingData.BeginTransaction();
      foreach (var column in cells) {
        double average = statisticInfo.GetAverage(column.Key);
        ReplaceIndicesByValue<double>(column.Key, column.Value, average);
      }
      preprocessingData.EndTransaction();
    }

    public void ReplaceIndicesByMedianValue(Dictionary<int, List<int>> cells) {
      preprocessingData.BeginTransaction();
      foreach (var column in cells) {
        double median = statisticInfo.GetMedian(column.Key);
        ReplaceIndicesByValue<double>(column.Key, column.Value, median);
      }
      preprocessingData.EndTransaction();
    }

    public void ReplaceIndicesByRandomValue(Dictionary<int, List<int>> cells) {
      preprocessingData.BeginTransaction();
      Random r = new Random();

      foreach (var column in cells) {
        double max = statisticInfo.GetMax<double>(column.Key);
        double min = statisticInfo.GetMin<double>(column.Key);
        double randMultiplier = (max - min);
        foreach (int index in column.Value) {
          double rand = r.NextDouble() * randMultiplier + min;
          preprocessingData.SetCell<double>(column.Key, index, rand);
        }
      }
      preprocessingData.EndTransaction();
    }

    public void ReplaceIndicesByLinearInterpolationOfNeighbours(Dictionary<int, List<int>> cells) {
      preprocessingData.BeginTransaction();
      foreach (var column in cells) {
        int countValues = preprocessingData.GetValues<double>(column.Key).Count();
        foreach (int index in column.Value) {
          // dont replace first or last values
          if (index > 0 && index < countValues) {
            int prevIndex = indexOfPrevPresentValue(column.Key, index);
            int nextIndex = indexOfNextPresentValue(column.Key, index);

            // no neighbours found
            if (prevIndex < 0 && nextIndex >= countValues) {
              continue;
            }
            double prev = preprocessingData.GetCell<double>(column.Key, prevIndex);
            double next = preprocessingData.GetCell<double>(column.Key, nextIndex);

            int valuesToInterpolate = nextIndex - prevIndex;

            double interpolationStep = (prev + next) / valuesToInterpolate;

            for (int i = prevIndex; i < nextIndex; ++i) {
              double interpolated = prev + (interpolationStep * (i - prevIndex));
              preprocessingData.SetCell<double>(column.Key, i, interpolated);
            }
          }
        }
      }
      preprocessingData.EndTransaction();
    }

    private int indexOfPrevPresentValue(int columnIndex, int start) {
      int offset = start - 1;
      while (offset >= 0 && searchLogic.IsMissingValue(columnIndex, offset)) {
        offset--;
      }

      return offset;
    }

    private int indexOfNextPresentValue(int columnIndex, int start) {
      int offset = start + 1;
      while (offset < preprocessingData.Rows && searchLogic.IsMissingValue(columnIndex, offset)) {
        offset++;
      }

      return offset;
    }

    public void ReplaceIndicesByMostCommonValue(Dictionary<int, List<int>> cells) {
      preprocessingData.BeginTransaction();
      foreach (var column in cells) {
        if (preprocessingData.IsType<double>(column.Key)) {
          ReplaceIndicesByValue<double>(column.Key, column.Value, statisticInfo.GetMostCommonValue<double>(column.Key));
        } else if (preprocessingData.IsType<string>(column.Key)) {
          ReplaceIndicesByValue<string>(column.Key, column.Value, statisticInfo.GetMostCommonValue<string>(column.Key));
        } else if (preprocessingData.IsType<DateTime>(column.Key)) {
          ReplaceIndicesByValue<DateTime>(column.Key, column.Value, statisticInfo.GetMostCommonValue<DateTime>(column.Key));
        } else {
          throw new ArgumentException("column with index: " + column.Key + " contains a non supported type.");
        }
      }
      preprocessingData.EndTransaction();
    }

    public void ShuffleWithRanges(IEnumerable<IntRange> ranges) {
      // init random outside loop
      Random random = new Random();

      preprocessingData.BeginTransaction();
      // process all given ranges - e.g. TrainingPartition, Trainingpartition
      foreach (IntRange range in ranges) {
        List<Tuple<int, int>> shuffledIndices = new List<Tuple<int, int>>();

        // generate random indices used for shuffeling each column
        for (int i = range.End; i > range.Start; --i) {
          int rand = random.Next(range.Start, i);
          shuffledIndices.Add(new Tuple<int, int>(i, rand));
        }

        ReOrderToIndices(shuffledIndices);
      }
      preprocessingData.EndTransaction();
    }

    public void ReOrderToIndices(IEnumerable<int> indices) {
      List<Tuple<int, int>> indicesTuple = new List<Tuple<int, int>>();

      for (int i = 0; i < indices.Count(); ++i) {
        indicesTuple.Add(new Tuple<int, int>(i, indices.ElementAt(i)));
      }

      ReOrderToIndices(indicesTuple);
    }

    public void ReOrderToIndices(IList<System.Tuple<int, int>> indices) {
      preprocessingData.BeginTransaction();
      for (int i = 0; i < preprocessingData.Columns; ++i) {
        if (preprocessingData.IsType<double>(i)) {
          reOrderToIndices<double>(i, indices);
        } else if (preprocessingData.IsType<string>(i)) {
          reOrderToIndices<string>(i, indices);
        } else if (preprocessingData.IsType<DateTime>(i)) {
          reOrderToIndices<DateTime>(i, indices);
        }
      }
      preprocessingData.EndTransaction();
    }

    private void reOrderToIndices<T>(int columnIndex, IList<Tuple<int, int>> indices) {

      List<T> originalData = new List<T>(preprocessingData.GetValues<T>(columnIndex));

      // process all columns equally
      foreach (Tuple<int, int> index in indices) {
        int originalIndex = index.Item1;
        int replaceIndex = index.Item2;

        T replaceValue = originalData.ElementAt<T>(replaceIndex);
        preprocessingData.SetCell<T>(columnIndex, originalIndex, replaceValue);
      }
    }
  }
}