[Numpy-discussion] obtain indexes of a sort ?
Simon Burton
simon at arrowtheory.com
Wed Apr 26 16:41:04 EDT 2006
Is it possible to obtain a permutation (array of indices)
representing the transform that sorts an array ? Is there a numpy way
of doing this ?
I can do it in python as:
a = [ 6, 5, 99, 2 ]
idxs = range(len(a))
z = zip(idxs,a)
def zcmp(u,v):
if u[1]<=v[1]:
return -1
return 1
z.sort( zcmp )
idxs = [u[0] for u in z] # <--- permutation
Simon.
--
Simon Burton, B.Sc.
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ANU Canberra 2601
Australia
Ph. 61 02 6249 6940
http://arrowtheory.com
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