pairedTTest - multiple declarations
Function pairedTTest
Paired T test. Tests the hypothesis that the mean difference between corresponding elements of before and after is testMean. Alternatives are Alt.less, meaning the that the true mean difference (before[i] - after[i]) is less than testMean, Alt.greater, meaning the true mean difference is greater than testMean, and Alt.twoSided, meaning the true mean difference is not equal to testMean.
before and after must be input ranges with elements implicitly convertible to double and must have the same length.
Returns
A ConfInt containing the T statistic, the P-value, and the boundaries of the confidence interval for the mean difference between corresponding elements of sample1 and sample2 at the specified level.
References
http://en.wikipedia.org/wiki/Student%27s_t-test
Function pairedTTest
Compute a paired T test directly from summary statistics of the differences between corresponding samples.
Examples
float[] data1 = [8, 6, 7, 5, 3, 0, 9];
float[] data2 = [3, 6, 2, 4, 3, 6, 8];
// Calculate summary statistics on difference explicitly.
MeanSD summary;
foreach(i; 0..data1 .length) {
summary .put(data1[i] - data2[i]);
}
// Test the null hypothesis that the mean difference between corresponding
// elements (data1[i] - data2[i]) is greater than 5 against the null that it
// is <= 5. Calculate confidence intervals at 99%.
auto result = pairedTTest(summary, 5, Alt .twoSided, 0.99);
// This is equivalent to:
auto result2 = pairedTTest(data1, data2, 5, Alt .twoSided, 0.99);
References
http://en.wikipedia.org/wiki/Student%27s_t-test