public void SignTestConstructorTest()
{
// Example from http://probabilityandstats.wordpress.com/2010/02/28/the-sign-test-more-examples/
double[] sample =
{
1, 1, 2, 2, 3, 3, 4, 5, 5, 6, 7, 7, 8, 10,
20, 22, 25, 27, 33, 40, 42, 50, 55, 75, 80
};
SignTest target = new SignTest(sample, hypothesizedMedian: 30);
Assert.AreEqual(OneSampleHypothesis.ValueIsDifferentFromHypothesis, target.Hypothesis);
Assert.AreEqual(0.043285, target.PValue, 1e-4);
Assert.IsTrue(target.Significant);
}
public void SignTestConstructorTest()
{
// Example from http://www.unm.edu/~marcusj/1Samplesign.pdf
double[] sample =
{
1, 1, 2, 2, 3, 3, 4, 5, 5, 6, 7, 7, 8, 10,
20, 22, 25, 27, 33, 40, 42, 50, 55, 75, 80
};
SignTest target = new SignTest(sample, hypothesizedMedian: 30);
// Wolfram Alpha gives 0.02896
// GNU R gives 0.04329
Assert.AreEqual(OneSampleHypothesis.ValueIsDifferentFromHypothesis, target.Hypothesis);
Assert.AreEqual(0.043285, target.PValue, 1e-4);
Assert.IsTrue(target.Significant);
}
public void SignTestConstructorTest2()
{
// This example has been adapted from the Wikipedia's page about
// the Z-Test, available from: http://en.wikipedia.org/wiki/Z-test
// We would like to check whether a sample of 20
// students with a median score of 96 points ...
double[] sample =
{
106, 115, 96, 88, 91, 88, 81, 104, 99, 68,
104, 100, 77, 98, 96, 104, 82, 94, 72, 96
};
// ... could have happened just by chance inside a
// population with an hypothesized median of 100 points.
double hypothesizedMedian = 100;
// So we start by creating the test:
SignTest test = new SignTest(sample, hypothesizedMedian,
OneSampleHypothesis.ValueIsSmallerThanHypothesis);
// Now, we can check whether this result would be
// unlikely under a standard significance level:
bool significant = test.Significant; // false (so the event was likely)
// We can also check the test statistic and its P-Value
double statistic = test.Statistic; // 5
double pvalue = test.PValue; // 0.99039
Assert.AreEqual(96, sample.Median());
Assert.AreEqual(statistic, 5);
Assert.AreEqual(pvalue, 0.99039459228515625);
}
