Introduction - If you have any usage issues, please Google them yourself
SWTEST Shapiro-Wilk parametric hypothesis test of composite normality.
[H, pValue, SWstatistic] = SWTEST(X, ALPHA, TAIL) performs
the Shapiro-Wilk test to determine if the null hypothesis of
composite normality is a reasonable assumption regarding the
population distribution of a random sample X. The desired significance
level, ALPHA, is an optional scalar input (default = 0.05).
TAIL indicates the type of test (default = 1).