#region License Information
/* HeuristicLab
* Copyright (C) 2002-2008 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 .
*/
#endregion
using System;
using System.Collections.Generic;
using System.Text;
using System.Xml;
using HeuristicLab.Core;
using HeuristicLab.Data;
using HeuristicLab.DataAnalysis;
using System.Linq;
using HeuristicLab.GP.Interfaces;
using HeuristicLab.Modeling;
namespace HeuristicLab.GP.StructureIdentification {
public class VariableFrequencyBasedImpactCalculator : OperatorBase {
public VariableFrequencyBasedImpactCalculator()
: base() {
AddVariableInfo(new VariableInfo("VariableFrequency", "List of variable frequencies over all iterations", typeof(ItemList), VariableKind.In));
AddVariableInfo(new VariableInfo("RelativeFrequencyVariableImpact", "Variable impacts", typeof(ItemList), VariableKind.New | VariableKind.Out));
}
public override IOperation Apply(IScope scope) {
ItemList variableFrequencies = GetVariableValue>("VariableFrequency", scope, true, false);
if (variableFrequencies != null) {
var inputVariables = from x in variableFrequencies[0]
select ((StringData)x).Data;
var frequencies = from x in variableFrequencies.Skip(1)
let row = from v in x
select ((DoubleData)v).Data
select row;
Dictionary qualityImpacts = Calculate(inputVariables, frequencies);
ItemList varImpacts = GetVariableValue("RelativeFrequencyVariableImpact", scope, true, false);
if (varImpacts == null) {
varImpacts = new ItemList();
scope.AddVariable(new HeuristicLab.Core.Variable(scope.TranslateName("RelativeFrequencyVariableImpact"), varImpacts));
}
varImpacts.Clear();
foreach (KeyValuePair p in qualityImpacts) {
ItemList row = new ItemList();
row.Add(new StringData(p.Key));
row.Add(new DoubleData(p.Value));
varImpacts.Add(row);
}
}
return null;
}
private static Dictionary Calculate(
IEnumerable inputvariables,
IEnumerable> frequencies) {
int nVariables = inputvariables.Count();
int iterations = frequencies.Count();
// allocate lists of frequencies for each variable
List[] frequencyTrajectory = new List[nVariables];
for (int i = 0; i < nVariables; i++) {
frequencyTrajectory[i] = new List();
}
foreach (var iterationFrequency in frequencies) {
int varIndex = 0;
if (iterationFrequency.Count() != frequencyTrajectory.Length) throw new ArgumentException();
foreach (var varIterationFrequency in iterationFrequency) {
frequencyTrajectory[varIndex++].Add(varIterationFrequency);
}
}
double[] impacts = new double[nVariables];
// calculate impacts as integral over the whole run
for (int variableIndex = 0; variableIndex < nVariables; variableIndex++) {
double baseLine = frequencyTrajectory[variableIndex][0];
for (int i = 0; i < iterations; i++) {
impacts[variableIndex] += (frequencyTrajectory[variableIndex][i] - baseLine);
}
impacts[variableIndex] /= iterations - 1;
}
Dictionary result = new Dictionary();
int j = 0;
foreach (string variableName in inputvariables) {
result[variableName] = impacts[j++];
}
return result;
}
}
}