Plotting contour using "contourf" command

Dear all,

Thanks in advance for your help! I would like to plot a contour of pressure data on a square surface, but the problem is in a square surface there is a hole, that means there is no data at that area, and i have pressure data on the remaining area. I have coordinates where the pressure data available. How can i control this area where the hole is situated? Please help me.

Thanks Raj