How can i read data from a text file with parfor or spmd .i have to read as two workers and to combine the result lastly.please reply soon..

How can i read data from a text file with parfor or spmd .i have to read as two workers and to combine the result lastly.please reply soon..

Answer 1

[Edric Ellis]

Something like this?

spmd
  fh = fopen(sprintf('file_%d.txt', labindex), 'rt');
  data = fscanf(fh, '%f');
  fclose(fh);
  gcat(data, 1); % GCAT combines the data
end

[shyni]

spmd fh = fopen(sprintf('in_file2_%d.txt', labindex), 'rt'); data = fscanf(fh, '%f'); fclose(fh); gcat(data, 1); % GCAT combines the data end

I have tried this code,But i got the following errors...please tell me the reason...

Error using spmd_feval (line 8) Error detected on lab(s) 1

Error in macode_parallel (line 2) fh = fopen(sprintf('in_file2_%d.txt', labindex), 'rt');

Caused by:

    Invalid file identifier.  Use fopen to generate a valid file
    identifier.

    Error stack:
    (No remote error stack)

[Edric Ellis]

Looks like your file name is incorrect. You could try adding

spmd
  fname = sprintf(...);
  fh = fopen(fname, 'rt');
  if fh == -1
    error('Could not read file: %s', fname);
  end
  ...
end

This will indicate which file couldn't be found.