how can I convert one square wave to impulses ?

I have the following picture and I want to convert it to impulse for counting how many picks there are. How can I count this picks ? , forexample # 4 for this picture .

Answer 1

[Mischa Kim]

Onur, you could simply take the derivative of the signal, provided that it is somewhat well behaved. See example below:

 t   = 0:0.1:20;
 x   = square(t,5) + 0.1*rand(1,length(t)); % noisy square wave
 val = +1;                                  % deriv treshold value
 num = length(find(diff(x)>val));           % data points with deriv > threshold
 disp(num)
 plot(t,x)

[Onur PEKER]

Thank you for your kind answer This is what I searched.