#region License Information
/* HeuristicLab
* Copyright (C) 2002-2018 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.Linq;
using HeuristicLab.Core;
namespace HeuristicLab.Encodings.SymbolicExpressionTreeEncoding {
//This class should not be used anymore. Use HeuristicLab.Random.RandomEnumberable instead
//This could not be fixed right now, because the algorithm behavior would be modified => version increment
[Obsolete("This class will be removed in the future, because the functionality is provided in HeuristicLab.Random.RandomEnumerable.")]
public static class EnumerableExtensions {
[Obsolete("This method should not be used anymore. Use the extensions provided by HeuristicLab.Random.RandomEnumberable instead.")]
public static T SelectRandom(this IEnumerable xs, IRandom random) {
var list = xs as IList;
if (list != null) {
return list[random.Next(list.Count)];
} else {
list = xs.ToList();
return list[random.Next(list.Count)];
}
}
[Obsolete("This method should not be used anymore. Use the extensions provided by HeuristicLab.Random.RandomEnumberable instead.")]
public static T SelectRandom(this IEnumerable xs, IEnumerable weights, IRandom random) {
var list = xs as IList;
var weightsList = weights as IList;
if (list == null) {
list = xs.ToList();
}
if (weightsList == null) {
weightsList = weights.ToList();
}
if (list.Count != weightsList.Count) throw new ArgumentException("Number of elements in enumerations doesn't match.");
if (list.Count == 0) throw new ArgumentException("Enumeration is empty", "xs");
double sum = weightsList.Sum();
double r = random.NextDouble() * sum;
double agg = 0;
for (int i = 0; i < list.Count; i++) {
agg += weightsList[i];
if (agg > r) return list[i];
}
// should never happen
throw new InvalidOperationException();
}
}
}