Figure rendered with OpenGL shows distorted data

Hi,

I'm running MATLAB 7.13.0.564 (R2011b)

I believe the code below illustrates a bug in the OpenGL renderer. The two plots generated contain the same data but the visual results are quite different.

t0=now;N=1e3;y=cumsum(randn(1,N));t=linspace(t0,t0+1,N);figure;plot(t,y);figure;plot(t,y);set(gcf,'renderer','opengl');

The distortion is much less severe when t0 is set to 0 instead of now.

I have a plot containing transparency which needs the OpenGL renderer but it's distorting my data. Can anyone help me with this?

Thank you!

Answer 1

[Walter Roberson]

Yes, setting to the OpenGL renderer has problems when the datapoints are close enough together. If you plot(1:length(y),y) you will not see the same problem. But compare

plot((1:1000)/100000000,y)

to

plot((1:1000)/1000000000,y)