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From: <HIDDEN>
Newsgroups: comp.soft-sys.matlab
Subject: Re: Complex Matrix Row Deletion
Date: Sun, 17 Jul 2011 14:17:27 -0500
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On 7/17/2011 1:00 PM, curoch wrote:
> Hi all,
>
> My problem is as follows:
>
> - I have a large matrix which may be exemplified in the following
> manner
>
> A = [1 1 23
> 1 1 24
...
> 2 -1 4 ]
> - My aim is to analyse the elements in the third column for each set
> where the values in column 1 and 2 are equal.

i
> - Upon analysing, I need to delete the row which has the smallest value
> in column 3.
>
> For example, applying this to matrix A
>
> The first set is [ 1 1 23
> 1 1 24] hence deleting the first row

 >> idx=A(:,1)==A(:,2);
 >> z=A(idx,3)

z =

     23
     24

 >> A(idx(1),:)=[]
A =
      1     1    24
      1    -1    34
      1    -1    45
      2     1    77
      2     1    12
      2    -1     4

 >>
>
> Matrix A thus becomes
>
> A = [ 1 1 23
> 1 -1 34
> 2 1 12
> 2 -1 4]
>
...

I don't see the above from the description and the matrix given but 
perhaps the previous manipulations will be of some benefit in selecting 
and deselecting desired rows, etc., ...

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