private void btStatistics_Click(object sender, EventArgs e)
{
StatisticsForm statisticsForm = new StatisticsForm(chart, functionName);
statisticsForm.Show();
}
private void btStatistic6_Click(object sender, EventArgs e)
{
StatisticsForm statisticsForm = new StatisticsForm(chartCombined, FUNCTION_NAME);
statisticsForm.Show();
}