public void ConstructorTest2_not_exact()
{
// 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:
var test = new WilcoxonSignedRankTest(sample,
hypothesizedMedian, OneSampleHypothesis.ValueIsSmallerThanHypothesis);
// Now, we can check whether this result would be
// unlikely under a standard significance level:
bool significant = test.Significant; // true (so the median of the students is
// significantly lower than 100, more than what could have been due to chance)
// We can also check the test statistic and its P-Value
double statistic = test.Statistic; // 40.0
double pvalue = test.PValue; // 0.0080210309581972838
/*
* Test against R:
* a <- c(106, 115, 96, 88, 91, 88, 81, 104, 99, 68, 104, 100, 77, 98, 96, 104, 82, 94, 72, 96)
* wilcox.test(a, mu=100, alternative='less') # V = 40, p-value = 0.01385
*
* Wilcoxon signed rank test with continuity correction
*
* data: a
* V = 40, p-value = 0.01385
* alternative hypothesis: true location is less than 100
*
* Warning messages:
* 1: In wilcox.test.default(a, mu = 100, alternative = "less") :
* cannot compute exact p-value with ties
* 2: In wilcox.test.default(a, mu = 100, alternative = "less") :
* cannot compute exact p-value with zeroes
*/
Assert.IsFalse(test.StatisticDistribution.Exact);
Assert.AreEqual(96, sample.Median());
Assert.AreEqual(statistic, 40.0);
Assert.AreEqual(pvalue, 0.01414652553632656, 1e-5);
Assert.AreEqual(DistributionTail.OneLower, test.Tail);
}
protected override void EndProcessing()
{
var hypo = TestingHelper.GetOneSampleHypothesis(Alternate);
var test = new WilcoxonSignedRankTest(
_data.ToArray(),
HypothesizedMean,
hypo,
Exact ? true : (Nullable <bool>)null,
!NoAdjustForTies)
{
Size = Size
};
WriteObject(test);
}
public void WilcoxonSignedRankTestConstructorTest3()
{
// Example from https://onlinecourses.science.psu.edu/stat414/node/319
double[] sample =
{
35.5, 44.5, 39.8, 33.3, 51.4, 51.3, 30.5, 48.9, 42.1, 40.3,
46.8, 38.0, 40.1, 36.8, 39.3, 65.4, 42.6, 42.8, 59.8, 52.4,
26.2, 60.9, 45.6, 27.1, 47.3, 36.6, 55.6, 45.1, 52.2, 43.5,
};
double hypothesizedMedian = 45;
var target = new WilcoxonSignedRankTest(sample, hypothesizedMedian);
Assert.AreEqual(232.5, target.StatisticDistribution.Mean);
Assert.AreEqual(2363.75, target.StatisticDistribution.Variance);
Assert.AreEqual(OneSampleHypothesis.ValueIsDifferentFromHypothesis, target.Hypothesis);
Assert.AreEqual(200, target.Statistic);
Assert.AreEqual(0.510, target.PValue, 1e-3); // 510 in linked page
Assert.IsFalse(target.Significant);
target = new WilcoxonSignedRankTest(sample, hypothesizedMedian, OneSampleHypothesis.ValueIsDifferentFromHypothesis);
Assert.AreEqual(232.5, target.StatisticDistribution.Mean);
Assert.AreEqual(2363.75, target.StatisticDistribution.Variance);
Assert.AreEqual(OneSampleHypothesis.ValueIsDifferentFromHypothesis, target.Hypothesis);
Assert.AreEqual(200, target.Statistic);
Assert.AreEqual(0.510, target.PValue, 1e-3);
Assert.IsFalse(target.Significant);
target = new WilcoxonSignedRankTest(sample, hypothesizedMedian, OneSampleHypothesis.ValueIsGreaterThanHypothesis);
Assert.AreEqual(232.5, target.StatisticDistribution.Mean);
Assert.AreEqual(2363.75, target.StatisticDistribution.Variance);
Assert.AreEqual(OneSampleHypothesis.ValueIsGreaterThanHypothesis, target.Hypothesis);
Assert.AreEqual(200, target.Statistic);
Assert.AreEqual(0.75135350754785524, target.PValue, 1e-10);
Assert.IsFalse(target.Significant);
target = new WilcoxonSignedRankTest(sample, hypothesizedMedian, OneSampleHypothesis.ValueIsSmallerThanHypothesis);
Assert.AreEqual(232.5, target.StatisticDistribution.Mean);
Assert.AreEqual(2363.75, target.StatisticDistribution.Variance);
Assert.AreEqual(OneSampleHypothesis.ValueIsSmallerThanHypothesis, target.Hypothesis);
Assert.AreEqual(200, target.Statistic);
Assert.AreEqual(0.25520903378968796, target.PValue, 1e-10);
Assert.IsFalse(target.Significant);
}
public void ConstructorTest2_exact()
{
// 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:
var test = new WilcoxonSignedRankTest(sample,
hypothesizedMedian, OneSampleHypothesis.ValueIsSmallerThanHypothesis,
exact: true);
// Now, we can check whether this result would be
// unlikely under a standard significance level:
bool significant = test.Significant; // true (so the median of the students is
// significantly lower than 100, more than what could have been due to chance)
// We can also check the test statistic and its P-Value
double statistic = test.Statistic; // 40.0
double pvalue = test.PValue; // 0.012226104736328125
/*
* Test against R:
* a <- c(106, 115, 96, 88, 91, 88, 81, 104, 99, 68, 104, 100, 77, 98, 96, 104, 82, 94, 72, 96)
* wilcox.test(a, mu=100, alternative='less') # V = 40, p-value = 0.01385
*/
Assert.IsTrue(test.StatisticDistribution.Exact);
Assert.AreEqual(96, sample.Median());
Assert.AreEqual(statistic, 40.0);
Assert.AreEqual(pvalue, 0.012226104736328125, 1e-10);
Assert.AreEqual(DistributionTail.OneLower, test.Tail);
}
public void WilcoxonSignedRankTestConstructorTest2()
{
// Example from https://onlinecourses.science.psu.edu/stat414/node/319
double[] sample = { 5.0, 3.9, 5.2, 5.5, 2.8, 6.1, 6.4, 2.6, 1.7, 4.3 };
double hypothesizedMedian = 3.7;
var target = new WilcoxonSignedRankTest(sample, hypothesizedMedian);
Assert.AreEqual(OneSampleHypothesis.ValueIsDifferentFromHypothesis, target.Hypothesis);
// Absolute differences and original signs
double[] delta = { +1.3, +0.2, +1.5, +1.8, +0.9, +2.4, +2.7, +1.1, +2.0, +0.6 };
double[] signs = { +1.0, +1.0, +1.0, +1.0, -1.0, -1.0, +1.0, -1.0, -1.0, +1.0 };
double[] ranks = { +5.0, +1.0, +6.0, +7.0, +3.0, +9.0, +10, +4.0, +8.0, +2.0 };
Assert.AreEqual(40, target.Statistic);
Assert.AreEqual(0.232, target.PValue, 1e-3);
Assert.IsFalse(target.Significant);
}
public void WilcoxonSignedRankTestConstructorTest()
{
double[] sample = { 17, 50, 45, 59.8, 21.74, 16, 9, 15.43, 5.12, 40, 35, 13.35, 13.4 };
double hypothesizedMedian = 7.38;
var target = new WilcoxonSignedRankTest(sample, hypothesizedMedian);
Assert.AreEqual(OneSampleHypothesis.ValueIsDifferentFromHypothesis, target.Hypothesis);
double[] delta = { 9.62, 42.62, 37.62, 52.42, 14.36, 8.62, 1.62, 8.05, 2.26, 32.62, 27.62, 5.97, 6.02 };
double[] ranks = { 7, 12, 11, 13, 8, 6, 1, 5, 2, 10, 9, 3, 4 };
Assert.IsTrue(delta.IsEqual(target.Delta, 1e-6));
Assert.IsTrue(ranks.IsEqual(target.Ranks, 1e-6));
Assert.AreEqual(89, target.Statistic);
Assert.AreEqual(0.003, target.PValue, 1e-3);
Assert.IsTrue(target.Significant);
}
public void WilcoxonSignedRankTestConstructorTest3()
{
// Example from https://onlinecourses.science.psu.edu/stat414/node/319
double[] sample =
{
35.5, 44.5, 39.8, 33.3, 51.4, 51.3, 30.5, 48.9, 42.1, 40.3,
46.8, 38.0, 40.1, 36.8, 39.3, 65.4, 42.6, 42.8, 59.8, 52.4,
26.2, 60.9, 45.6, 27.1, 47.3, 36.6, 55.6, 45.1, 52.2, 43.5,
};
double hypothesizedMedian = 45;
var target = new WilcoxonSignedRankTest(sample, hypothesizedMedian);
Assert.AreEqual(OneSampleHypothesis.ValueIsDifferentFromHypothesis, target.Hypothesis);
Assert.AreEqual(200, target.Statistic);
Assert.AreEqual(0.510, target.PValue, 1e-3);
Assert.IsFalse(target.Significant);
}
public void ConstructorTest2()
{
// 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:
WilcoxonSignedRankTest test = new WilcoxonSignedRankTest(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; // 40.0
double pvalue = test.PValue; // 0.98585347446367344
Assert.AreEqual(96, sample.Median());
Assert.AreEqual(statistic, 40.0);
Assert.AreEqual(pvalue, 0.98585347446367344);
}
private void Button_Click(object sender, RoutedEventArgs e)
{
List <double> vpop1 = new List <double>();
List <double> vpop2 = new List <double>();
try
{
//Try comma separated instead
var TextScores = pop1.Text.Replace(" ", string.Empty).Split(',').ToList();
foreach (var S in TextScores)
{
vpop1.Add(double.Parse(S));
}
TextScores = pop2.Text.Replace(" ", string.Empty).Split(',').ToList();
foreach (var S in TextScores)
{
vpop2.Add(double.Parse(S));
}
}
catch
{
return;
}
var Hypo = TwoSampleHypothesis.FirstValueIsGreaterThanSecond;
switch (((Button)sender).Content.ToString())
{
case "Dif":
Hypo = TwoSampleHypothesis.ValuesAreDifferent;
break;
case "Less":
Hypo = TwoSampleHypothesis.FirstValueIsSmallerThanSecond;
break;
case "More":
Hypo = TwoSampleHypothesis.FirstValueIsGreaterThanSecond;
break;
default:
break;
}
dynamic test, testWilcoxon;
if (vpop1.Count == vpop2.Count)
{
test = new PairedTTest(vpop1.ToArray(), vpop2.ToArray(), Hypo);
testWilcoxon = new TwoSampleWilcoxonSignedRankTest(vpop1.ToArray(), vpop2.ToArray(), Hypo);
}
else
{
test = new TTest(
vpop1.ToArray(),
vpop2[0],
OneSampleHypothesis.ValueIsSmallerThanHypothesis);
testWilcoxon = new WilcoxonSignedRankTest(
vpop1.ToArray(),
vpop2[0],
OneSampleHypothesis.ValueIsSmallerThanHypothesis);
}
results.Text = "T-Test:\n Significant: " + test.Significant + "\n p-value: " + test.PValue +
"\nMannWhitneyWilcoxon Test:\n Significant: " + testWilcoxon.Significant + "\n p-value: " + testWilcoxon.PValue;
}
public void RCompatibilityTest()
{
// Test case from https://github.com/accord-net/framework/issues/389
/*
* // Test against R:
* a <- c(35, 15, 25, 10, 45, 20, 21, 22, 30, 17)
* b <- c(20, 17, 23, 15, 49, 19, 24, 26, 33, 18)
*
* wilcox.test(a, mu=13, alternative="greater") # V = 53, p-value = 0.00293
* wilcox.test(a, mu=13, alternative="two.sided") # V = 53, p-value = 0.005859
* wilcox.test(a, mu=13, alternative="less") # V = 53, p-value = 0.998
*/
var s1 = new double[] { 35, 15, 25, 10, 45, 20, 21, 22, 30, 17 };
var wilcoxonSignedRankTest = new WilcoxonSignedRankTest(s1, 13, OneSampleHypothesis.ValueIsGreaterThanHypothesis);
Assert.IsTrue(wilcoxonSignedRankTest.StatisticDistribution.Exact);
Assert.AreEqual(0.00293, wilcoxonSignedRankTest.PValue, 1e-5);
Assert.AreEqual(53, wilcoxonSignedRankTest.Statistic);
Assert.AreEqual(true, wilcoxonSignedRankTest.Significant);
Assert.AreEqual(OneSampleHypothesis.ValueIsGreaterThanHypothesis, wilcoxonSignedRankTest.Hypothesis);
wilcoxonSignedRankTest = new WilcoxonSignedRankTest(s1, 13, OneSampleHypothesis.ValueIsDifferentFromHypothesis);
Assert.IsTrue(wilcoxonSignedRankTest.StatisticDistribution.Exact);
Assert.AreEqual(0.005859, wilcoxonSignedRankTest.PValue, 1e-5);
Assert.AreEqual(53, wilcoxonSignedRankTest.Statistic);
Assert.AreEqual(true, wilcoxonSignedRankTest.Significant);
Assert.AreEqual(OneSampleHypothesis.ValueIsDifferentFromHypothesis, wilcoxonSignedRankTest.Hypothesis);
wilcoxonSignedRankTest = new WilcoxonSignedRankTest(s1, 13, OneSampleHypothesis.ValueIsSmallerThanHypothesis);
Assert.IsTrue(wilcoxonSignedRankTest.StatisticDistribution.Exact);
Assert.AreEqual(0.998, wilcoxonSignedRankTest.PValue, 1e-2);
Assert.AreEqual(53, wilcoxonSignedRankTest.Statistic);
Assert.AreEqual(false, wilcoxonSignedRankTest.Significant);
Assert.AreEqual(OneSampleHypothesis.ValueIsSmallerThanHypothesis, wilcoxonSignedRankTest.Hypothesis);
wilcoxonSignedRankTest = new WilcoxonSignedRankTest(s1, 13, OneSampleHypothesis.ValueIsGreaterThanHypothesis, exact: false);
Assert.AreEqual(0.0054134606385656562, wilcoxonSignedRankTest.PValue, 1e-5);
Assert.AreEqual(53, wilcoxonSignedRankTest.Statistic);
Assert.AreEqual(true, wilcoxonSignedRankTest.Significant);
Assert.IsFalse(wilcoxonSignedRankTest.StatisticDistribution.Exact);
Assert.AreEqual(OneSampleHypothesis.ValueIsGreaterThanHypothesis, wilcoxonSignedRankTest.Hypothesis);
wilcoxonSignedRankTest = new WilcoxonSignedRankTest(s1, 13, OneSampleHypothesis.ValueIsDifferentFromHypothesis, exact: false);
Assert.AreEqual(0.0093441130022048919, wilcoxonSignedRankTest.PValue, 2e-3);
Assert.AreEqual(53, wilcoxonSignedRankTest.Statistic);
Assert.AreEqual(true, wilcoxonSignedRankTest.Significant);
Assert.IsFalse(wilcoxonSignedRankTest.StatisticDistribution.Exact);
Assert.AreEqual(OneSampleHypothesis.ValueIsDifferentFromHypothesis, wilcoxonSignedRankTest.Hypothesis);
wilcoxonSignedRankTest = new WilcoxonSignedRankTest(s1, 13, OneSampleHypothesis.ValueIsSmallerThanHypothesis, exact: false);
Assert.AreEqual(0.9959773812567192, wilcoxonSignedRankTest.PValue, 1e-5);
Assert.AreEqual(53, wilcoxonSignedRankTest.Statistic);
Assert.AreEqual(false, wilcoxonSignedRankTest.Significant);
Assert.IsFalse(wilcoxonSignedRankTest.StatisticDistribution.Exact);
Assert.AreEqual(OneSampleHypothesis.ValueIsSmallerThanHypothesis, wilcoxonSignedRankTest.Hypothesis);
}
