Extract values between successive start stop indexes from a signal

Hello everyone,

I have data with defined start and stop indexes. However for further processing i have to extract only the values between those starts stops for computing several variables. The circles below are the starts and the stars are the stops. I need to perform computational operations only between those intervals. So is there a way to extract only the data between those regions?

Really appreciate any help. Thanks a lot.

Answer 1

[darova]

I think there are tricks with vectorizing but i like simple and clear solution even it's slower

x0                % your data
x = [];
ind = [1 4 7 9 12 15];    % i want data between (1,4) (7,9) (12,15)
for i = 1:2:length(ind)-1
    j = ind(i):ind(i+1)
    x = [x x0];
end

[Christos Chalitsios]

Thank you a lot darova for your aswer really nice solution. I have a question though. I forgot to mention that the i have extracted the starts and stops as different vectors. Is there a way to merge them in way that after the first start value will go the fisrt stop value and not the second start? below i paste the code for computing start and stop indexes.

Thanks a lot for your help!!!

for k=1:length(locs)
    Ftemp=ftotal;
    i=locs(k);
    
    while Ftemp(i)>=find(Ftemp(i)>=300 & Ftemp(i)>0,1)
          i=i-1;
          while Ftemp(i-1)-Ftemp(i)<0
              i=i-1;
          end 
    end
    startindex1(k)=i;
end

for k=1:length(locs)-1
    Ftemp=ftotal;
    i=locs(k);
    
    while Ftemp(i)>=find(Ftemp(i)>=300 & Ftemp(i)>0,1)
          i=i+1;
          while Ftemp(i+1)-Ftemp(i)<0
              i=i+1;
          end
    end
        stopindex1(k)=i;
end

[darova]

Of course!

ind = [];
for k = 1:length(locs)
    curr_ind = startIndex1(k):stopIndex1(k);
    ind = [ind curr_ind];
end