From: ara.t.howard@...
Date: 2006-12-29T01:34:50+09:00
Subject: Re: Sorting an NArray

On Fri, 29 Dec 2006, mekondelta wrote:

>
> I have a 2 dimensional array using NArray and wish to sort the values based
> on the values in column zero or row zero.
>
> How can I achieve this using NArray? I can't even seem to get the basic sort
> working:-
>
> matrix.sort(0)
>
> gives me a "..blah..:in `sort': undefined method `<=>' for nil:NilClass
> (NoMethodError)"
>
> I know I can supply a block to the sort method but the documentation, such
> that it is at:-
>
> http://narray.rubyforge.org/SPEC.en
>
> isn't that informative and implies that the above line should work?
>
> Any ideas greatly appreciated.
>
> Cheers, Chris.
>

   harp:~ > ruby -r narray -e'  p NArray.to_na([ [5,4,3], [2,1,0] ])  '
   NArray.int(3,2):
   [ [ 5, 4, 3 ],
     [ 2, 1, 0 ] ]

   harp:~ > ruby -r narray -e'  p NArray.to_na([ [5,4,3], [2,1,0] ]).shape  '
   [3, 2]

   harp:~ > ruby -r narray -e'  p NArray.to_na([ [5,4,3], [2,1,0] ]).sort  '
   NArray.int(3,2):
   [ [ 0, 1, 2 ],
     [ 3, 4, 5 ] ]

#
# sort the 0th thru 0th dims
#
   harp:~ > ruby -r narray -e'  p NArray.to_na([ [5,4,3], [2,1,0] ]).sort(0)  '
   NArray.int(3,2):
   [ [ 3, 4, 5 ],
     [ 0, 1, 2 ] ]

#
# sort the 0th thru 1st dims
#
   harp:~ > ruby -r narray -e'  p NArray.to_na([ [5,4,3], [2,1,0] ]).sort(1)  '
   NArray.int(3,2):
   [ [ 0, 1, 2 ],
     [ 3, 4, 5 ] ]

-a
-- 
if you find yourself slandering anybody, first imagine that your mouth is
filled with excrement.  it will break you of the habit quickly enough. - the
dalai lama