Matlab's parfor will probably work on the case above, I don't know exactly how they do it, but it's pretty smart usually.
x2 = []; n = 10; parfor i = 1:n x2 = [x2, i]; end x2 I have to say the Julia doc is not super clear, it says: "Notice that the reduction operator can be omitted if it is not needed. However, this code will not initialize all of a, since each process will have a separate copy if it. Parallel for loops like these must be avoided. Fortunately, distributed arrays can be used to get around this limitation, as we will see in the next section." But it doesn't really comes back to this example in the distributed array section. On Wednesday, March 5, 2014 9:17:45 PM UTC+1, Jake Bolewski wrote: > > Hi Jason, > > I don't really understand what you are trying to do but the problem is > that the array a is not read-only in this context. > From the manual: Using “outside” variables in parallel loops is perfectly > reasonable if the variables are read-only. > > See the parallel section of the manual: > http://julia.readthedocs.org/en/latest/manual/parallel-computing/ > > The way you are using a is not amenable to parallelization as you have a > clear data dependency for each iteration. > > Best, > Jake > > On Wednesday, March 5, 2014 2:51:11 PM UTC-5, Jason Solack wrote: >> >> i'm sorry, yes i did! >> >> On Wednesday, March 5, 2014 2:49:11 PM UTC-5, Jake Bolewski wrote: >>> >>> Is j = 1000000 a typo (did you mean 1:1000000)? >>> >>> >>> On Wednesday, March 5, 2014 2:41:51 PM UTC-5, Jason Solack wrote: >>>> >>>> i'm trying to check out how Julia handles parallel for loops and i'm >>>> getting some errors >>>> >>>> i'm not sure if it's because i'm working with a single array and i >>>> can't append to this in parallel, so i thought i'd ask >>>> >>>> nprocs() >>>> addprocs(6) >>>> >>>> tic() >>>> onPass = 1 >>>> a = Array(Int64, 0) >>>> @parallel for i = 1:100000, j=10000 >>>> a = [a, i*j] >>>> onPass = onPass + 1 >>>> if onPass % 10000 == 0 >>>> println("on pass ", onPass) >>>> end >>>> end >>>> toc() >>>> >>>> is this not possible in parallel? >>>> >>>> Thank you again for all your answers! >>>> >>>> jason >>>> >>>
