For two samples x and y from normal distributions with unknown means and unknown variances, perform an F-test of the null hypothesis of equal variances.
Under the null, the test statistic f follows an F-distribution with df_num and df_den degrees of freedom.
With the optional argument string alt, the alternative of interest
can be selected. If alt is "!=" or "<>", the null
is tested against the two-sided alternative var (x) != var
(y). If alt is ">", the one-sided alternative
var (x) > var (y) is used. Similarly for "<", the
one-sided alternative var (x) > var (y) is used. The
default is the two-sided case.
The p-value of the test is returned in pval.
If no output argument is given, the p-value of the test is displayed.
Package: statistics