Xristos Xristoou <saxr...@gmail.com> writes: > i have create an image processing python function. > > my system have 4 cores + 4 threads. > > i want to use multiprocessing to speed up my function,but anytime to > use multiprocessing packages my function is not faster and is 1 minute > slowly. any idea why ?first time use multiprocessing packages. > > main function : > > if __name__ == '__main__': > in_path="C:/Users/username/Desktop/in.tif" > out_path="C:/Users/username/Desktop/out.tif" > myfun(in_path, out_path) > time=3.4 minutes > > with multiprocessing map : > > if __name__ == '__main__': > p = Pool(processes=4) > in_path="C:/Users/username/Desktop/in.tif" > out_path="C:/Users/username/Desktop/out.tif" > result = p.map(myfun(in_path,out_path))
Don't you get an error telling you that map needs another argument? map is intended to be used like this: p.map(f, [1, 2, 3]) the function is applied to the elements drawn from the iterable second argument. Each application runs in a separate process form the pool and the results are combined together into a list result. So you could process multiple file in parallel using this method but it can't run your function on that one input file in parallel. <snip> -- Ben. -- https://mail.python.org/mailman/listinfo/python-list
