private void AddFunc_Click(object sender, RoutedEventArgs e)
{
if (graph != null)
{
int index = graph.CustomFunctions.Count;
string name = "Func" + index;
FunctionGraph gp = new FunctionGraph(name);
gp.AssignParentGraph(graph);
graph.AddCustomFunction(gp);
FunctionView cp = new FunctionView(gp);
cp.OnRemove += Cp_OnRemove;
Stack.Children.Add(cp);
}
}