MATLAB postpones disp calls when doing demanding calculations. Why is that?

I am implementing an algorithm in MATLAB. Among other things it calculates the shortest paths etc. so it's quite demanding for my old computer. I'开发者_JAVA技巧ve put in disp() calls through out the program to see what's happening all the time.

However when starting on a particulary heavy for loop the disp() seemes not to be called until the loop is over even though it comes before the loop. Why is that? I thought that MATLAB was really executing sequentially or am I just choking it with too many calculations and the disp() calls get the lowest priority?

I am almost certain it is because of EDT.

That's the function drawnow() is for. See article of Yair Altman for good explanation.

Summary: MATLAB graphics is Java Swing and operations happen on a special thread - Event Dispatch Thread (EDT). Calling drawnow(); flushes event queue and updates figure window.