Correctly indexing a parfor loop

Hi all,

I converted a nested for loo into a unique parfor loop. The nested for loop looked like this:

for RIPETIZIONE = 1:N_RIPETIZIONI
    for k=1:size(lambda_tol_vector)
        %do things
    end
end

Now, the parfor loop takes on the following values:

parfor n=1:N_RIPETIZIONI*K

hence merging into a single loop the nested loops of before.

Now, inside the "outer" nested loop (for RIPETIZIONE = 1:N_RIPETIZIONI), but outside the inner loop (for k=1:size(lambda_tol_vector)), there was this part:

scv=size(columns_validation_test,2);   
    
for counter_columns = 1:scv
    COLONNA_SELEZIONATA=columns_validation_test(counter_columns);
    Ctest=zeros(size(A.Value));
    Ctest(:,COLONNA_SELEZIONATA)=C(:,COLONNA_SELEZIONATA);
    Cvalidation=C-Ctest;
    for j=1:size(lambdavector)
        RMSE_initial_test{counter_columns}(j)=sqrt(sum2(Diff_sq_initial{j}.*Ctest)/sum(Ctest(:)));
        RMSE_final_corrected_validation{counter_columns}(j)=sqrt(sum2(Diff_sq_corrected{j}.*Cvalidation)/sum(Cvalidation(:)));
        RMSE_final_test{counter_columns}(j)=sqrt(sum2(Diff_sq{j}.*Ctest)/sum(Ctest(:)));
        RMSE_final_corrected_test{counter_columns}(j)=sqrt(sum2(Diff_sq_corrected{j}.*Ctest)/sum(Ctest(:)));
            
    end
        [~,arg_min_temp_1]=min(RMSE_final_corrected_validation{counter_columns});
end

which I need now to includde in the unique parfor loop with a pope indexing. Fo instance, Diff_sq_initial, Diff_sq_corrected and Diff_sq are all defined withing the parfor loop with an index of n in the new loop (whereas previosuly they were indexed with k inside the for k=1:size(lambda_tol_vector) loop).

Is there a way to properly indexing those variables so that they fit the new parfor loop?

Thaank you

[Alvaro]

If the last code block was between the outer and inner for loop, why would the variables be indexed by k if that is the index of the inner loop?

Also, please explain what is the end goal here, are you trying to parallelize your code? Combining your nested for loops into a parfor loop is not necessarily the optimal way of doing this.