On Wed, Sep 29, 2010 at 9:03 PM, Damien Morton <[email protected]> wrote: > On Thu, Sep 30, 2010 at 3:28 AM, Robert Kern <[email protected]> wrote: >> On Wed, Sep 29, 2010 at 12:00, Pauli Virtanen <[email protected]> wrote: >>> Wed, 29 Sep 2010 11:15:08 -0500, Robert Kern wrote: >>> [clip: inplace addition with duplicates] >>>> Use numpy.bincount() instead. >>> >>> It might be worthwhile to add a separate helper function for this >>> purpose. Bincount makes a copy that could be avoided, and it is difficult >>> to find if you don't know about this trick. >> >> I'm fairly certain that most of the arrays used are fairly small, as >> such things are reckoned. I'm not sure that in-place modification >> would win us much. And I'm not sure what other name for the function >> would make it easier to find. AFAICT, using bincount() this way is not >> really a "trick"; it's just the right way to do exactly this job. If >> anything, "x.fill(0);x[i] += 1" is the "trick". > > bincount only works for gathering/accumulating scalars. Even the > 'weights' parameter is limited to scalars.
Do you mean that bincount only works with 1d arrays? I also think that this is a major limitation of it. > > I propose the name 'gather()' for the helper function that does this. I don't think "gather" is an obvious name to search for. Josef > _______________________________________________ > NumPy-Discussion mailing list > [email protected] > http://mail.scipy.org/mailman/listinfo/numpy-discussion > _______________________________________________ NumPy-Discussion mailing list [email protected] http://mail.scipy.org/mailman/listinfo/numpy-discussion
