Why is the rectangle command so much slower on the new graphics engine?

Hi folks,

i am just comparing the performance in plotting a lot of filled circles via the rectangle command. My benchmark is Release 2010b and i want to switch to Release 2015b.

I could not believe that i found 2015b being 5 times slower! Same machine, same renderer. (Doesn't depend on the renderer, though.)

Here is my example code including time measurement.

z=0;
for exp=1:0.2:5,
  n=round(10^exp);cntr=rand(n,2);rad=rand(n,1);z=z+1;figure;hold on;set(gcf,'Renderer','opengl');
  t1=clock;
  for i=1:n,
    h=rectangle('Position',[cntr(i,1)-rad(i),cntr(i,2)-rad(i),2*rad(i),2*rad(i)],'Curvature',[1,1],'FaceColor','b','EdgeColor','none');
  end
  t2=clock;result(z)=etime(t2,t1);nn(z)=n;delete(gcf);
end

Who has an idea to draw so many filled(!) circles (patches or anything, not pure lines as in viscircles) at a competetive speed also in 2015b?

For a major application of mine this really is a big drawback!

Answer 1

[Walter Roberson]

You can find some performance information at

http://blogs.mathworks.com/graphics/2015/01/20/performance-scaling/

http://blogs.mathworks.com/graphics/2015/06/09/object-creation-performance/