The following example is taken from Conover (1980, p. 224). It involves the mixing time of two mixing machines using a total of 10 batches of a certain kind of batter, five batches for each machine. The null hypothesis is not rejected at the 5-percent level of significance.
using System; using Imsl; using Imsl.Stat; public class WilcoxonRankSumEx1 { public static void Main(String[] args) { double[] x = new double[]{7.3, 6.9, 7.2, 7.8, 7.2}; double[] y = new double[]{7.4, 6.8, 6.9, 6.7, 7.1}; WilcoxonRankSum wilcoxon = new WilcoxonRankSum(x, y); Console.Out.WriteLine ("p-value = " + wilcoxon.Compute().ToString("0.0000")); } }
p-value = 0.1412 Imsl.Stat.WilcoxonRankSum: "x.length" = 5 and "y.length" = 5. Both sample sizes, "x.length" and "y.length", are less than 25. Significance levels should be obtained from tabled values. Imsl.Stat.WilcoxonRankSum: At least one tie is detected between the samples.Link to C# source.