while( abs( $mutRate - 0.01) > 1e-16 ) {
    ++$iter;
    $k *= $mutRate * 100;
    map $_ /= ( $mutRate * 100), @$_ for @lnPAM;
    @matrix = map[ map exp( $_ ), @$_ ], @lnPAM;
    $mutRate = sum map{ $freq[ $_ ] * ( 1 - $matrix[ $_ ][ $_ ] ) } 0..19;
    printf "After %d iteration(s), k=%f, RateMutation=%f\n", $iter, $k, $mutRate;
}