Conover's Two-Sample Squared Ranks Test for Equality of Variance

Performs two-sample squared ranks test for equality of variance.

Performs the nonparametric squared ranks test on quality of variance for two samples. Based on Conover (1981), 'Practical Nonparametric Statistics', pp. 239-248.

Uses normal approximation for for m >10 (MATLAB fxn norminv or table if norminv unavailable). Uses normal approximation if ties exist. Uses tabulated critical values from Conover if small samples sizes and no ties.

Input:
x vector;
y vector;
type I error rate;
alternative hypothesis type (upper, lower, two-sided)

Output:
squared ranks test statistic if no ties;
squared ranks test statistic if ties;
decision (1 reject; 0 fail to reject);
Type I error rate;
alternative hypothesis type;
lower side critical value;
upper side critical value.