please help with polar plot

Hi guys I am doing PhD study on obseving the flow velocities in pipe flow partailly filled. I sketched a figure1 showing a pipe with dimeter 60 cm and flow depth is 15 cm, the red points showing where the velocities in x direction are measured '' you can assume any values''. I need to plot that into contour style in Matlab.. just like the figure2 shown below. thank you figure1 http://i49.tinypic.com/3150568.jpg

figure2 http://i49.tinypic.com/2notb5.jpg

Answer 1

[Walter Roberson]

Instead of treating it as a polar plot, treat it as a rectangular coordinate plot, assigning NaN to the z coordinate for each point where there should not be any data. Then contourf().

[Eslam]

Thanx Walter, I know this idea, but it is gonna take long time to identify the circle, i hope u see what i mean.

[Walter Roberson]

You can draw the circle outline on top of the contourf() plot.

[Eslam]

Mr Walter,Thanx again for your help.. could you please do an example of that, assume any values.