KaleidaGraph calculates the differences between each set of pairs, and ranks the absolute values of the differences from low to high. If there are no tied ranks, an exact p value is calculated. If there are tied ranks (or a large number of samples), the p value is calculated from a Gaussian approximation.
KaleidaGraph is a thoughtfully designed graphing and data analysis application for research scientists, as well as for those in business and engineering fields. It produces publication-quality graphs, and easily converts the most complex data into a functional display.