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Re: Removing equal elements from an array [message #49831 is a reply to message #49761]

Thu, 17 August 2006 09:07

news.qwest.net
Messages: 137
Registered: September 2005

Senior Member

"Julio" <julio@cpa.unicamp.br> wrote in message
news:1155653196.084429.65000@74g2000cwt.googlegroups.com...
> Another question... please help me!!
>
> I have an array 'A' with two columns, latitudes and longitudes, and
> several lines. A need to make another array with the elements of A that
> don't repeat. An example:
>
> A[0]=[20.4, 40.3, 50.2, 50.2]
> A[1]=[30.2, 60.2, 32.4, 32.4]
>
> Note that the third and fourth pairs are the same (50.2, 32.4). So, I
> need to make another array and remove one of the pairs. So, I would
> have:
>
> A[0]=[20.4, 40.3, 50.2]
> A[1]=[30.2, 60.2, 32.4]
>
> Do you have any idea how to do that??
>
> Thanks!
>
> Julio

If I follow you correctly, you want to find unique pairs of numbers right?
How about combining the pairs into one number, and running uniq() on that?

For instance:

A = fltarr(2,4)
A[0,*]=[20.4, 40.3, 50.2, 50.2]
A[1,*]=[30.2, 60.2, 32.4, 32.4]
combo = A[0,*]*1000 + A[1,*]
indices = UNIQ(combo, SORT(combo))

{and of course, keep in mind the comments by JD and others about
using uniq on floats. You might want to change the lats and lon to integers
and then use uniq: (something like)
int_a = round(a*100)

Cheers,
bob

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[Message index]

		Removing equal elements from an array By: Julio[1] on Tue, 15 August 2006 07:46
		Re: Removing equal elements from an array By: JD Smith on Thu, 17 August 2006 14:21
		Re: Removing equal elements from an array By: news.qwest.net on Thu, 17 August 2006 13:32
		Re: Removing equal elements from an array By: news.qwest.net on Thu, 17 August 2006 13:06
		Re: Removing equal elements from an array By: JD Smith on Thu, 17 August 2006 10:59
		Re: Removing equal elements from an array By: news.qwest.net on Thu, 17 August 2006 09:07
		Re: Removing equal elements from an array By: Julio[1] on Wed, 16 August 2006 12:42
		Re: Removing equal elements from an array By: R.Bauer on Wed, 13 September 2006 23:32

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