sub gen_param {
    my ( $file, $file_neg, $nofseq ) = @_;
    my @param_groups;

    foreach my $wlen ( 8, 15, 20 ) {
        foreach my $fract ( 0.8, 0.5 ) {
            foreach my $q ( $nofseq, $nofseq * 1.5 ) {
                push @param_groups, {
                    file              => $file,
                    file_neg          => $file_neg,
                    submt_len         => 5,
                    submt_d           => 1,
                    e                 => 0,
                    W_size            => $wlen,
                    lp                => $fract * $wlen,
                    support_threshold => $q,
                    min_inst_lower    => $q,
                    min_inst_upper    => ( 3 * $q ),
                    polyTA_lim        => 0.8,
                    poly_lim          => 0.8,
                };
            }   
        } 
    }
    return @param_groups;
}