private void step3_Click(object sender, EventArgs e)
{
tips.Text = "3. Activate hidden layer nodes(sigmoid)";
sh1.Text = Math.Round(AnnInstance.Sigmoid(Convert.ToDouble(sh1.Text)), 3).ToString();
sh2.Text = Math.Round(AnnInstance.Sigmoid(Convert.ToDouble(sh2.Text)), 3).ToString();
}