Mex file is faster when it is called from command but slower when it is called inside a code!!!

Hi everyone,

I am working on an optimization problem which needs to run my model several times and test for different constraints and cost. For this reason I need a model which can be simulated quickly. The solution which I found is to convert the model to a mex file. I have converted a part of the model to mex file... Now when I run this part alone to check if it is faster than m file, I observe that it is faster about 4 times. However, when I plug this mex file to the rest of the model, the result becomes slower....

Does any of you have an idea what can be a possible reason? Thanks in advanced, Reza

[Jan]

How did you measure the timings? I do not think that anybody can guess the reasons without seeing the code.

Answer 1

[Walter Roberson]

If you have a "clear all" call, get rid of it.

[Aragorn_]

Thanks dear Walter for your answer,

I have a "clear variables" which I removed it, but I didn't see any difference!

[Walter Roberson]

Is this Simulink or MATLAB directly?

[Aragorn_]

MATLAB.

The model is about a chemical reactor which contains about 1700 ode's.

[Walter Roberson]

Could you profile the code to determine where it is spending its time?