sub create_chart {
    my (%args) = @_;

    die "No ydata\n" unless exists $args{ydata};
    
    Chart::Gnuplot::DataSet->new(
        xdata => \@yfix,
        style => "lines",
        color => "dark-gray",
        linetype => "dash",
        width => 1,
        %args
    );
}


my $tempmin = create_chart(ydata => \@minit);
my $tempmax = create_chart(ydata => \@maxit, color => 'red');