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Re: Finding Clusters

  • To: mathgroup at smc.vnet.net
  • Subject: [mg117118] Re: Finding Clusters
  • From: James Stein <mathgroup at stein.org>
  • Date: Thu, 10 Mar 2011 06:09:10 -0500 (EST)

Here is one way:

Given a list such as

list = {{x ->1.1, y-> 2.2}, {x ->3.3, y ->4.4}}

you can remove the "x's and y's" this way:
     list = list /. Rule[a_, b_] -> b

You could discover this yourself by examining the structure of 'list' with
'FullForm":
    list // FullForm

hth, James

On Wed, Mar 9, 2011 at 4:02 AM, Martin Vavpoti=C4=8D
<martin.vavpotic at gmail.com>wrote:

> Hello everyone.
>
> I have a large array of numbers (1000 ==D72). I wish to find clusters in
> that mesh of numbers but the FindClusters method is giving me a hard
> time. I think it's because of those non-numeric leftovers from NSolve
> (x -> and y ->).
>
> {{x -> 9.95043, y -> 0.201587}, {x -> -0.0507389,
>  y -> 0.39451}, {x -> -0.0502288 + 0.192544 I,
>  y -> 0.199992 - 2.42154*10^-6 I}, {x -> -0.0502288 - 0.192544 I,
>  y -> 0.199992 + 2.42154*10^-6 I}, <<992>>, {x -> -0.0507405,
>  y -> 0.394519}, {x -> -0.0502287 + 0.192544 I,
>  y -> 0.2}, {x -> -0.0502287 - 0.192544 I,
>  y -> 0.2}, {x -> -0.0507405, y -> 0.00548135}}
>
> I know that if you write something like %[[1,2,2]] you get only the
> numbers but I have a whole array here. How do I get the whole array to
> lose those y -> ?
>
> Help anyone?
>
>


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