The following surprisingly simple method picks items from an array with given probabilities:
// Return a random value where the values have the indicated // probabilities.// The probabilities must add up to 1.0.public static T PickWithProbability<T>(this T[] values, double[] probabilities){ // Pick a random probability. double prob = Rand.NextDouble(); // Find the selected item. for (int i = 0; i < values.Length; i++) { prob -= probabilities[i]; if (prob <= 0) return values[i]; } throw new Exception("Probabilities do not add up to 1.0");}
The method uses the Rand object's NextDouble method to pick a prob value between 0.0 and 1.0. It then loops through the probabilities, subtracting each from prob. When ...
