detecting no. of events

I have an array of 2000x1 = D .

i have a condition D>25. for D>25 higher than 20 sec i should count 1 event.

how can i do this in matlab?

Answer 1

[Thorsten]

If D contains an entry every second, you can use:

 D = randi(2000, 1, 20); % sample data

 di = diff([0 D > 25 0]);
 i1 = find(di == 1);
 i2 = find(di == -1);
 Nevents = nnz(i2 - i1 > 20);

[Heartrin]

Dimensions of matrices being concatenated are not
consistent.

Error in t (line 10)
di = diff([0 D > 25 0]);

this is the error if i use the above code

[Thorsten]

What's the size of D? If it is 20000x1 as you said in your original post, then it should work. If it is 1x20000, you have to use

di = diff([0; D > 25; 0]);

[Heartrin]

Thanks . you are awesome.