Thread Subject: How to average one of column and then duplicate each row to next row?

Dear all,

Please advice me some easier method to rearrange this question I'm trying to solve.

Cheers,
Michael

% original data
1 22 333 44 2222
2 33 444 55 4444
3 44 555 66 6666
4 55 666 77 8888
5 66 777 88 2222

% after matlab's arrangement, the new 5th column is the average of original 5th column
1 22 333 44 1111
1 22 333 44 1111
2 33 444 55 2222
2 33 444 55 2222
3 44 555 66 3333
3 44 555 66 3333
4 55 666 77 4444
4 55 666 77 4444
5 66 777 88 1111
5 66 777 88 1111

"Kuo-Hsien" <mchangks@hotmail.com> wrote in message <gmf1pe$jtm$1@fred.mathworks.com>...
> .......
> Please advice me some easier method to rearrange this question I'm trying to solve.
> .......

  On the basis of what I see in your example, it has nothing to do with an "average". You seem to be duplicating each row and dividing the fifth column by two.

  Call x the original data.

 [m,n] = size(x);
 x(:,n) = x(:,n)/2;
 x = reshape(repmat(x(:),1,2).',[],n);

Roger Stafford

Kuo-Hsien wrote:
...
> Please advice me some easier method to rearrange this question I'm trying to solve.
...
Easier than what, pray tell?

> % original data
> 1 22 333 44 2222
> 2 33 444 55 4444
> 3 44 555 66 6666
> 4 55 666 77 8888
> 5 66 777 88 2222
>
> % after matlab's arrangement, the new 5th column is the average of original 5th column
> 1 22 333 44 1111
> 1 22 333 44 1111
> 2 33 444 55 2222
> 2 33 444 55 2222
> 3 44 555 66 3333

The 5th column in the latter certainly isn't an average of the original;
rather it appears to be one-half the original value.

But, if that's what is wanted, something like the following is the
straightforward way...

 >> a = [1 22 333 44 2222;
         2 33 444 55 4444;
         3 44 555 66 6666;
         4 55 666 77 8888;
         5 66 777 88 2222];
 >> b=zeros(2*size(a,2),size(a,1));
 >> nrows=size(a,1);
 >> for i=1:nrows
      i2=2*i-1;
      b(i2,:)=a(i,:);
      b(i2,5)=a(i,5)/2;
      b(i2+1,:)=b(i2,:);
    end
 >> b
b =
            1 22 333 44 1111
            1 22 333 44 1111
            2 33 444 55 2222
            2 33 444 55 2222
            3 44 555 66 3333
            3 44 555 66 3333
            4 55 666 77 4444
            4 55 666 77 4444
            5 66 777 88 1111
            5 66 777 88 1111


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