foreach my $dataset (sort keys %datasets) {

 my $ttest = new Statistics::TTest;
 $ttest->load_data(\@{$datasets{$dataset}[0]},\@{$datasets{$dataset
+}[1]});
 print "$dataset - t_prob:\t$ttest->{t_prob}\n\n";

undef @$ttest;   # clear out old array data
undef %$ttest;   # get old hash data
}