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Topic: Compare two vectors and got indices of the identical numbers
Replies: 4   Last Post: Feb 16, 2013 9:14 PM

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Nasser Abbasi

Posts: 5,661
Registered: 2/7/05
Re: Compare two vectors and got indices of the identical numbers
Posted: Feb 16, 2013 7:52 PM
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On 2/16/2013 5:53 PM, Danny wrote:
> How to compare 2 vectors and got the indices of 2 identical numbers
>
> lets say I have matrix a

>>> a=[250;500;750;200;600;800;230;650;800]
>
> a =
>
> 250
> 500
> 750
> 200
> 600
> 800
> 230
> 650
> 800
>
> and I sort matrix a to matrix b
>

>>> b=sort(a)
>
> b =
>
> 200
> 230
> 250
> 500
> 600
> 650
> 750
> 800
> 800
>
> and I want to compare matrix b to matrix a to identify in which indices of matrix a is
>equal to the content of matrix b.
>
> For example for the number 230 in matrix b is located in the indices of #7 in matrix a
> or number 650 in matrix b is located in the indices of #8 in matrix a
>
> Thanks before for the answer
>
> Regards
>


one way:

-------------------------
a=[250;500;750;200;600;800;230;650;800];
b=sort(a,1);
N=length(a);
for i=1:N
[~,N(i)]=ismember(b(i),a);
end
N
--------------

4 7 1 2 5 8 3 9 9


--Nasser




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