Thread Subject:

contourf and contour from polar coordinates

hi guys,

i have recently come across data that I transformed from polar coordinates into an eucledian system. However, I am having issues with contourf and contour that i have never experienced before:

a.) somehow the contourf plot does not show any colours unless it is slightly rotated; does anybody have an idea why that is the case? (example images are here: http://i1195.photobucket.com/albums/aa382/rtaker/contourf_NotWorking.png not working and http://i1195.photobucket.com/albums/aa382/rtaker/contourf_rotated.png for slightly rotated (in the direct view in matlab the whole thing is coloured)

b.) using contour with about 1500 lines gives a neater result http://i1195.photobucket.com/albums/aa382/rtaker/contour1500.png However, I am wondering why the white triangulation (?) seem not decrease even though they are close to data-points as shown here: http://i1195.photobucket.com/albums/aa382/rtaker/contour1500_withDataPoints.png (the 'o' show the data points that are available).

Is there any advice you can give me? Ideally I would like to have a plot similar to this http://stackoverflow.com/questions/10856882/r-interpolated-polar-contour-plot in R or origin.

Hope someone can help me out.
Best regards

noone an ideas why things go wrong?

On Friday, August 17, 2012 9:30:08 PM UTC+12, Rafael wrote:
> noone an ideas why things go wrong?

Have you seen this:
http://www.mathworks.com/matlabcentral/fileexchange/14826-polar-contour-plot