MATLAB Function "on-line" computation

Hello everyone!

Many weeks ago I've tried to post the question about my problem, but it still unanswered, maybe because of formulations, so I decide to make the question as simple as it can be. Here it is:

Is there a way to make the calculations in matlab function something like "on-line"? This is what i mean: the input in MATLAB function changes relatively to normal value. So, MF block do some computations(to do this pretty simple MF squares the time moment, when the input signal was changed and transfer this value to the output).

If the value of input signal changed second time, MF block do the same, and so on.

The problem is how to do this. I tried many times, but did'nt get anywhere. Maybe it can't be done with MATLAB function block, so I want to know how it can be done.

If anyone can help me with this problem, it will be great.

Thanks in advance!