matlabpool open local (inside a loop)

Hey! I am making this script where I need to have matlabpool open local inside a loop because I would be executing the same code on different amounts of workers. The problem is that when I start my loop at i=1, and then put matlabpool open local i, matlab does not want to take i as the number of workers I want, I only can take a number instead of a variable. Is there any way of having matlabpool open local inside a loop and changing the amount of workers each time? Thanks!

Answer 1

[Walter Roberson]

matlabpool('open','local',i)

but are you sure that you want to allocate 1 worker to the first iteration, 2 workers to the second iteration, and so on ?

[Reynaldo]

Thank you so so so much!!! yeah I want to go from 1 worker to any number of workers available because we are doing some code benchmarking and we want to know exactly the difference in time in the execution of the code for each number of workers. Thanks!!

[Walter Roberson]

Be sure to allow for the fact that the first time any particular function is executed, MATLAB will spend some time doing JIT parsing and optimization.

[Reynaldo]

Oh I see, is there any way of making matlab do the JIT parsing and optimization over again each time a function is executed?

[Walter Roberson]

feature('jit','off'); feature('accel','off')

should do that. However, that isn't usually the best way to proceed as it will give distorted views of what MATLAB is able to do.

What you should do instead is run the code first, with any convenient number of workers (e.g., 1), and throw away that timing result, and then go through your loop.

You may also wish to use the user contribution "timeit", http://www.mathworks.com/matlabcentral/fileexchange/18798