On May 2, 8:47 pm, guillermo.castilla.castell...@gmail.com wrote:
> On May 1, 12:36 pm, Jeremy Bailin <astroco...@gmail.com> wrote:
>
>
>
>> On May 1, 1:47 pm, Jeremy Bailin <astroco...@gmail.com> wrote:
>
>>> On May 1, 12:13 pm, "chenb...@gmail.com" <chenb...@gmail.com> wrote:
>
>>>> Hello, everyone!
>
>>>> Is there anyone knows a routine in IDL that be capable to remove
>>>> duplicate elements from a multi-dimensional array efficiently? I 'm
>>>> now working with huge arrays, and I have written one by myself, it
>>>> works but is with low efficiency.
>
>>>> example of my problem:
>>>> the input array:
>>>> 1,10,9,100,200
>>>> 2,11,8,101,201
>>>> 2,11,8,101,201
>>>> 3,10,9,100,200
>>>> 4,7,12,99,199
>>>> 2,11,8,101,201
>
>>>> goal:
>>>> remove the duplicate elements with the same values for the second and
>>>> the third column.
>
>>>> expected output:
>>>> 1,10,9,100,200
>>>> 2,11,8,101,201
>>>> 4,7,12,99,199
>
>>>> Thanks for your help!
>
>>>> Bo
>
> If you don't have handy that ORD function Jeremy pointed out (I didn't
> know of it), and assuming your array is of byte type, you can do the
> following:
>
> input = [[1,10,9,100,200],[2,11,8,101,201],[2,11,8,101,201],$
> [3,10,9,100,200],[4,7,12,99,199],[2,11,8,101,201]]
>
> keep = Where(Histogram(1000L*input[1,*]+input[2,*], rev=r) GT 0)
> keep = r[r[keep]]
> print, input[*,keep[sort(keep)]]
> 1 10 9 100 200
> 2 11 8 101 201
> 4 7 12 99 199
>
> Cheers
>
> Guillermo
You can find ord at:
http://web.astroconst.org/jbiu/jbiu-doc/math/ord.html
-Jeremy.
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