Hi Cho,
Both methods work as expected:

   NPointD p1 = new NPointD(10.0, 10.0);

    // p1 X, Y does not change
    p1.Rotate(30.0);

	Name	Value	Type
▶	p1	{{X=11.4228307398045,Y=-8.33780174205278}}	Nevron.GraphicsCore.NPointD

    // p1 X, Y does not change
    p1.Translate(3.0, 3.0);

	Name	Value	Type
▶	p1	{{X=14.4228307398045,Y=-5.33780174205278}}	Nevron.GraphicsCore.NPointD

As you can see from the watch window in the debugger - please double-check how you use these methods and keep in mind that the NPointD is a structure so if you pass it by reference to a method the value will not change in the caller. Let us know if you meet any problems.

Best Regards,
Nevron Support Team

I am using the NPointD data type.
But the Rotate and Translate functions I need are not working.
I haven't tested other functions in the class, but I think it won't work.

Check the function operation of the class.

The example code is shown below.

NPoint p1 = new NPointD (10.0,10.0);

// p1 X, Y does not change
p1.Rotate(30.0);

// p1 X, Y does not change
p1.Translate (3.0,3.0);

please answer about my question.