How to create an if loop with conditions

Hi,

in my Time analysis i need to divide my vector 'pupil diameter' in 3 moments and for each one i have to calculate the median

and i did it in this way

%% TIME SPAN ANALYSIS 
time_1 = median(diametre(1:33000));
time_2 = median(diametre(33001:66000));
time_3 = median(diametre(66001:99000));

but not all my subject have vector length which reaches 99000 timestamps so i created a loop where i wrote:

for i=1:length(list)
    time_1 = median(diametre(1:33000));
    time_2 = median(diametre(33001:66000));
    if diametre > 66000
        time_3 = median(diametre(66001:99000));
    end

list is the list of my participant. When it comes to calculate time_3 then it tell me that the matrix exceed the dimension so it means that the loop doesnt work despite i check the length of the signal in all my participant before choosing where to cut

can you please help me write it correctly?

thank you very much in advance

Answer 1

[Walter Roberson]

if numel(diametre) > 66000

[GB92_R]

Hi,

thank you for your answer but it still tells me that the matrix exceed the dimension

[Walter Roberson]

if numel(diametre) >= 99000

[GB92_R]

it doesn't work either.

it stops at the first participant with a diameter length of 80000

and the error says

Undefined function or variable 'time_1'.

[Walter Roberson]

for i=1:length(list)

What is list ?

    time_1 = median(diametre(1:33000));

You do not appear to be using the value of i so it is not clear why you are looping there.

If list were empty, then after the for loop, time_1 would be undefined.

Be careful, when diametre is small, time_3 would be undefined.

[GB92_R]

yes, thank you

it works !