Accord.Tests.Statistics.TwoSampleZTestTest.PowerTest1 C# (CSharp) Method

        public void PowerTest1()
        {
            // Example from http://www.statpower.net/Content/310/Print%20Version%20--%20Power%20for%20the%202-Sample%20Z-Statistic.pdf

            double mean1 = 0.5;
            double mean2 = 0.0;
            double var1 = 0.5;
            double var2 = 0.5;
            int samples = 25;

            TwoSampleZTest test = new TwoSampleZTest(
                mean1, var1, samples,
                mean2, var2, samples);

            TwoSampleZTestPowerAnalysis pa = (TwoSampleZTestPowerAnalysis)test.Analysis;

            Assert.AreEqual(0.43, pa.Power, 0.01);

            pa.Power = 0.8;
            pa.ComputeSamples();

            double expectedSamples = 63;
            double actualSamples = Math.Ceiling(2 * pa.Samples1);

            Assert.AreEqual(expectedSamples, actualSamples);
        }