Matlab Runs Slower during each consecutive iteration

I have a simulation that i built that I run multiple time inside a for(or parfor) loop. I timed each iteration and noticed that it takes longer to complete each consecutive iteration. I have preallocated all my arrays so I know its not that.

Also, of concern is that if I finish it and re-run the simulation it will not start again at the faster speeds but run slowly, almost as if it picked up where it left off. But if I close matlab, log off windows, log back on, and re run it. I will start off running faster again.

I was wondering if there was some sort of memory that ends up filling up in matlab ans if so is there a way to clear it to run these simulations faster (without logging off windows).

Thank you,

Ryan

[Edric Ellis]

Could you clarify: what form is this simulation? (MATLAB code, Simulink model, ...) Does "clear classes" help things? Do you have persistent/global data anywhere? Do you really need to log off Windows to get back to the "fast" state - is it not sufficient simply to restart MATLAB? Have you checked that you're not increasing the size of your pre-allocated arrays?

Answer 1

[Jan]

Use the PROFILEr to find out, which lines take more time from interation to iteration.

As long as you do not find the actual slow part of the program, all our answers are wild mass guessing. See: PMWiki: WildMassGuessing

Answer 2

[Clemens]

One thing that happens often to me is that I forget to close invisible windows. (created by figure('visible','off') )

maybe try a:

close all

[Jan]

A similar problem appeared in this forum before: Images are added to an AXES, but the former images have not been deleted.

Answer 3

[Ryan]

This is a MATLAB code.

I'll give the clear classes a try.

No global or persistent variables are used.

The log off is required.

I've gone through and made sure I've pre-allocated all my arrays but I'll check again.

[Daniel Shub]

Does your program call any mex files or launch any processes external to MATLAB? What about file/IO read and writes?