Robert,Argsort doesn't preserve order by default because quicksort is not a stable sort. Try using the kind="merge" option and see what happens. Or try lexsort, which is targeted at just this sort of sort and uses merge sort. See the documentation here.
http://scipy.org/Numpy_Example_List#head-9f
Charles R Harris wrote:
> Robert,
>
> Modifying your example gives
>
> In [3]: import numpy as nm
>
> In [4]: a = nm.zeros( 1 )
> In [5]: b = nm.arange( 1 )
> In [6]: nm.alltrue( a.argsort(kind="merge" ) == b )
> Out[6]: True
Thanks for all the answers!
r.
Robert,Modifying your example givesIn [3]: import numpy as nmIn [4]: a = nm.zeros( 1 )In [5]: b = nm.arange( 1 )In [6]: nm.alltrue( a.argsort(kind="merge" ) == b )
Out[6]: TrueOn 6/8/06, Robert Cimrman <[EMAIL PROTECTED]> wrote:
Hi all,I have just lost some time to find a bug related to the
Travis Oliphant wrote:
> Robert Cimrman wrote:
>
>>I have just lost some time to find a bug related to the fact, that
>>argsort does not preserve the order of an array that is already sorted,
>>see the example below. For me, it would be sufficient to mention this
>>fact in the docstring, althou
Robert Cimrman wrote:
> Hi all,
>
> I have just lost some time to find a bug related to the fact, that
> argsort does not preserve the order of an array that is already sorted,
> see the example below. For me, it would be sufficient to mention this
> fact in the docstring, although having order
