Re: Union question
- To: mathgroup at smc.vnet.net
- Subject: [mg13922] Re: [mg13889] Union question
- From: BobHanlon at aol.com
- Date: Mon, 7 Sep 1998 01:22:47 -0400
- Sender: owner-wri-mathgroup at wolfram.com
Garrett,
See on-line help for Union and SameTest.
data = Table[Random[], {10}]
{0.51655,0.37473,0.877331,0.0649562,0.653698,0.114661,0.075878,0.0756202,
0.505527,0.341529}
closeEnough[x_, y_] := Abs[x-y] < 10^-1 (* In your case use 10^-12 *)
Union[data, SameTest->closeEnough]
{0.0649562,0.341529,0.505527,0.653698,0.877331}
Bob Hanlon
In a message dated 9/6/98 7:18:34 AM, gas2y at node4.unix.virginia.edu
wrote:
>I'm trying to take a very long list of real numbers and use the Union
>function on it to remove duplicates. The problem is that the real
>numbers that I consider to be the same, differ after their 12th decimal
>place. I have tried without sucess to use N and SetAccuracy functions
>on each element of the list Before using the Union Function, but to no
>Avail. Is there any quick way to take a long list, and remove
>duplicate elements by comparing only the first n significant digets of
>each element.