MATLAB: Contour plot quality in pdf problem

Question

Hello,

I recently installed R2015a and went on to produce a couple of standard graphs but they appear distorted in the pdf output as you can see below. Anyone knows how can I eliminate this?

Answer 1

http://uk.mathworks.com/matlabcentral/answers/162257-problem-with-patch-graphics-in-2014b-splits-in-two-along-diagonal#answer_158564