Non-Parametric Tests

At least one test must be selected.  Type a list of letters containing the
first one or two letters that are capitalized. Consult a statistics text for
more information about each test.
SIgn test =    The sign of the difference between pairs of values is noted. 
		The frequency of the least-frequent sign is compared with
		the frequency expected by chance.
Wilcoxon =	Like the SIgn test, but the absolute magnitude of the
		differences between pairs are ranked. Ranks associated with
		positive differences are compared with ranks aoociated with
		negative differences.
FRiedman =	Compares the average rank for each column with the average
		rank for all the other columns.
KRusdal-Wallis= One-way analysis of variance on ranks.  If there are only
		two groups, then the Mann-Whitney U-statistic is also given.
KEndall and
SPearman =	Correlations among ranks.

The data need not be ranks.  P3S computes the ranks before proceding.