When you specify the CHISQ option in the TABLES statement, PROC FREQ performs the following chi-square tests for each two-way table: Pearson chi-square, continuity-adjusted chi-square for 2 ×2 tables, ...

import math def chi2P(chi, df): """Return prob(chisq >= chi, with df degrees of freedom). df must be even. """ assert df & 1 == 0 # XXX If chi is very large, exp(-m ...