How can i see if the value occurs in an array for the first time?

I have an array called loadp (50*1 double). I would like to see if the value occurs in the respective cell (loop) for the first time. If so, something should be executed. if the value has already occurred in the previous runs, the value should ignored.

for i=1:numRows;
    %tmp = regexp(my_strings(i),'(?<=_l)\d+','match','once');
    %loadp(i,1) =  str2double(tmp)
    condition=any(diff(sort(loadp(i,1))) == 0)
    if condition==0
        %do something
        sadasd=2313
    else
        %do nothing
        ssd=213123
    end
end 

[Tommy]

Maybe either of these will work?

condition = ~ismember(loadp(i),loadp(1:i-1));
% or
condition = find(loadp==loadp(i),1) == i;

They should both check if i is the first index in loadp which contains loadp(i). I'm not sure which is better, or if some other way would beat both.

Or maybe I am misinterpreting the question?

[Philipp Mueller]

It works! Thank you Tommy :)

[Tommy]

Fantastic, happy to help!

(moved to an answer)

Answer 1

[Tommy]

Try one of these.

condition = ~ismember(loadp(i),loadp(1:i-1));
% or
condition = find(loadp==loadp(i),1) == i;

They should both check if i is the first index in loadp which contains loadp(i). I'm not sure which is better, or if some other way would beat both.