use Statistics::R;
sub     do_chi_squared_test_in_R {
        my $freqs = $_[0]; # arrayref of counts/frequencies for each choice
        my $R = Statistics::R->new(); # should really re-use R obj but let's not complicated things now.
        $R->send('library(MASS)');
        $R->set('freqs', $freqs);
        $R->run('res <- chisq.test(as.table(freqs))');
        my $chisquare = $R->get('res$statistic'); # single quotes please
        my $pvalue = $R->get('res$p.value');
        $R->stop();
        print "do_chi_squared_test_in_R : ".join(",",@$freqs)." : x2=$chisquare, pv=$pvalue\n";
        # returns [chi-squared-statistic, p-value]
        return [$chisquare, $pvalue]
}