Drawing the filled contour

Hi all, For example, i have a circular plate with diameter 50 cm. In the same circular plate there is a hole with 10 cm diameter at the center of circular plate. Now i have some pressure data at different locations on the circular plate (I know the coordinate of the data points). If there is no hole in the plate, i can draw the filled contour on the circular plate. Here, the problem is, hole is situated on the plate where there is no pressure data. If do contour, it will cover the all the plate including the area where the hole is situated. How can i exclude this hole portions to draw the filled contour using matlab.