Maureen, I believe Cameron answered your question. If you open teh JMP sample data table Iris.jmp, there is a GraphBuilder Contour plot script that produces this graph
![image.png image.png](https://community.jmp.com/t5/image/serverpage/image-id/14254i41DA991158C42468/image-size/large?v=v2&px=999)
Below is and example of sample data LittlePond.jmp's contour plot with an added column called Sea leve, that is "Below" when z < 0 and "Above" when z >=0.