Unable to use parfor with strcmpi

Hello, I am trying to use PARFOR in a loop which runs a strcmpi() function. The code is:

parfor i = 1:size(data_1,1)
      idx = find(strcmpi(data_1{i,1},data_2(:,1)));
      dd = data_2(idx,:); 
      for j = 1:size(dd,1)
          fprintf(file,'%s\t%s\n',dd{j,1},dd{j,2}); % print to file
      end
end

I am not able to slice the "data_2" which is a 31mn x 2 cell array due to which I am not able to run parfor. Can anyone suggest how I can modify this program for parfor? Moreover, will this effect the way I am printing the data in the file?

Thank you.

[Walter Roberson]

find(strcmpi(data_1{i,1},data_2(:,1)))

... you are expecting multiple matches?

Is either data_1(:,1) or data_2(:,1) a set of unique strings?

Answer 1

[Edric Ellis]

The variable data_2 is not being sliced because every iteration of the parfor loop needs access to the whole array. This is not an error though - the code analyzer warning is simply telling you that the code is incurring extra communication because the whole of data_2 is being sent to each worker.

[Anurag Passi]

So, why does the parpool sits idle and shuts off? Why am I not able to run it on parallel? What can be changed in this? Below is the actual error that I get.

[Walter Roberson]

You are running out of memory trying to send the data to all of the workers. The data is converted to a byte stream and then the byte stream is sent to the workers and the workers reconstruct the objects; this requires a temporary copy of the data that could have you running out of memory.

[Anurag Passi]

So I think maybe I should try some other way of working with this data. Thank you for your replies.

[Walter Roberson]

If either data_1(:,1) or data_2(:,1) are sets of unique strings then ismember() can be used before-hand to find the indexing.