How to generate a new array from if statement embedded in for loop

Hi MATLAB community,

I have a problem when I am trying to generate a new data array by processing it with an if statment embeded in a for loop.

Some backgroung: I have a cell array {181 x 1}, each of sub-cell arrays has a size 3059 x 5, double. Where 1st column is time point, 2nd cloumn is x_point, and column 5 is intensity.

I have created a separate array where I can set the intensity treshold. For instance it is column 5*0.8

I would like to generate a new data array that would contain only two columns x_point, and time_point that coreesponds to the time when value in the column 5 has droped bellow the intensity treshold. So this would be a new array with the size 3059 x 2.

I have tried to do that by embeding an if statement into for loop with the following code

Cellarray = accumarray(data(:,1),(1:size(data,1)),[],@(x){data(x,:)});
% Set the drop in intesity. If the intesity droped by 20% the intensity drop
% would be 0.2
Intensity_drop=0.2;
%Calculate intesity treashold for the first set of cells
Intensity_treshold=[Cellarray{1,1}(:,5)]*(1-Intensity_drop);
%number of pcells
numbpcells=numel(Intensity_treshold);
%number of time frames
time_frames=numel(Cellarray);
for k=1:time_frames
    for i=1:numbpcells
    if Cellarray{k,1}(i,5)<=Intensity_treshold(i)
        N=[Cellarray{k,1}(i,2),k];
        break
    else
        return
    end
    
    end
end

I was expecting it to run trough all the iterations until it gets to the value which is bellow treshold, and then diplay the data in a form of new array N. But this did not happen. Or at least Idid not get any N data as a return.

Could you sudgest what I did wrong, or is there another way to obtain the data set I am after.

I would be really greatfull,

[darova]

return means end of script execution. Try without it

[Iuliia Myrgorodska]

I've tried to delete this part

        break
    else
        return
        end
        

It gave me N a 1 x2 array from the very last itteration

If I put

        N{i}=[Cellarray{k,1}(i,2),k];
      

It also wouldn't work the way it should

Basicaly I the loop to stop once it hit the number bellow trreshold, the way this data set is built the data after this point will be bellow treshold as well so they would owerite the original value, and therefore the I would get only the last time point, while the data I am trying to acces are the time point when the value droped bellow treshold for the very first time

Answer 1

[Reshma Nerella]

Hi,

I understand that you want to terminate the execution of both inner and outer loops once the condition is satisfied. It can be done using a variable.

status = 1; % initialising a variable
for k=1:time_frames
    for i=1:numbpcells
        if Cellarray{k,1}(i,5)<=Intensity_treshold(i)
            N=[Cellarray{k,1}(i,2),k];
            status = 0; % required condition is met
        end
        
        if status == 0
            break % break inner for loop
        end
    end
    
    if status == 0
        break  % break outer for loop
    end
end