On Mon, Mar 24, 2014 at 11:05 AM, Alan G Isaac <[email protected]> wrote:
> > On Mon, Mar 24, 2014 at 12:08 PM, Alan G Isaac > >> what is the preferred idiom for a descending sort? > > > On 3/24/2014 12:13 PM, [email protected] wrote: > > adding [::-1] just creates a new view, pretty low cost. > > > I meant when you need to sort on a key (another vector). > > Currently I'm just reversing the result of argsort with [::-1] > but this changes the sort order (relative to a stable descending sort). > > For integer types you can use the complement as the key In [9]: ~arange(4, dtype=uint8) Out[9]: array([255, 254, 253, 252], dtype=uint8) In [10]: ~arange(4, dtype=int8) Out[10]: array([-1, -2, -3, -4], dtype=int8) For float types you would need to use the negative. Chuck
_______________________________________________ NumPy-Discussion mailing list [email protected] http://mail.scipy.org/mailman/listinfo/numpy-discussion
