How can I vectorize this piece of code for loading cross-validation from file ?

So I am supposed to load the cross-validation folds from a file (10 iterations, each is 10-folds, so a total of 100, arranged sequentially in a 1-dimensional array). I have attached the file below. The problem is my code uses for loops intensively and I would like to vectorise it, here is my code:

input_filename = 'cv_yeast.mat';
cv = load(input_filename);
nfolds= 10;
niters = 10;

for loop =1:niters   

      for i = 1 : nfolds     
          teIdx = cv.cv{((loop-1)*nfolds + i)};        
          trIdx = [];        
          for j = 1 : nfolds
              if j ~= i                
                  trIdx = [trIdx; cv.cv{(loop - 1)*nfolds + j}];
              end
          end 
          % Processing goes here
   end
  end

For some reasons I don't want to vectorise the 2 outer for loops, just the inner one. Can anyone help me, thank you very much :)

Answer 1

[Walter Roberson]

Possibly

jv = setdiff(1 : nfolds, i);
trIdx  = vertcat( cv.cv{(loop - 1)*nfolds + jv} );

[Dang Manh Truong]

Thanks a lot, man