The command is twoway contour.
Or pull down the Graphics menu.
Either way, you can draw
Let us show you how this works.
Imagine you start with these data:
That’s almost an ordinary two-way scatter of 126 observations, except that it is of three variables, and the third variable is encoded by color.
Anyway, start with those data, specify that you want Shepard interpolation, and you get this:
Or, specify that you want the default thin-plate spline, and you get this: