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Topic: Avergaing Matrix.
Replies: 1   Last Post: Feb 4, 2013 4:36 AM

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 Jos Posts: 1,268 Registered: 10/24/08
Re: Avergaing Matrix.
Posted: Feb 4, 2013 4:36 AM
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"Linus " <linus.ang@live.com> wrote in message <ken744\$5je\$1@newscl01ah.mathworks.com>...
> Hi,
>
> I need to acquire the average of a matrix with n columns and m rows.
>
> For example,
> 1 2 3 4
> 2 2 3 4
> 3 2 3 4
>
> Is there any code to compute the average of the first 2 columns and last 2 columns separately as shown?
> 1.5 3.5
> 2.0 3.5
> 2.5 3.5
>
> Thank you.

Use proper indexing to select the input to MEAN:

A = [1 2 3 4 ; 2 2 3 4 ; 3 2 3 4]
B = [mean(A(:,[1 2]),2) mean(A(:,[3 4]),2)]

See the help of MEAN to understand why it's second input is a 2.

~ Jos

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