On Thu, Jul 22, 2010 at 5:09 PM, marco cammarata <[email protected]> wrote: > Hi, > > any idea why the simple code below is so slow ? > > import numpy as n > from time import time as t > > dims = (640,480) > m = n.random.random( dims ) > > l=[] > > for i in range(200): > l.append(m) > > t0=t() > b=n.array(l) > print t()-t0 > > > To convert the list into an array takes about 5 sec ... >
There was a recent thread that covers similar ground. "Stacking arrays along new dimension in front" http://www.mail-archive.com/[email protected]/msg26772.html I think the fastest way was to do b = n.concatenate(a_[None] for a_ in l) but I could be mistaken, and there should probably be a more general solution to this problem. Skipper _______________________________________________ NumPy-Discussion mailing list [email protected] http://mail.scipy.org/mailman/listinfo/numpy-discussion
