fastest way to read in every m lines of a file sequentially?

I need to read in every 100 lines of a very large file. Then I so some calculations with the data of those 100 lines then I get the next 100 lines (in order) and do the same set of calculations...and repeat until the last set of 1000 lines of the very large file. I cannot read in the entire large file at once, as it is too big.

What is the best (fastest) way to do this?

I already know the basic structure:

 while(~feof(myfile)) 
       a=fgetl(myfile)
 end

Thanks!

Answer 1

[Azzi Abdelmalek]

fid=fopen(myfile)
k=0;
a=cell(1,100)
while ~feof(fid)
  k=k+1
  a{k}=fgetl(fid)
  if mod(k,100)==0
      %do your calculations
   end
end
fclose(fid)