sort indexing

[Doug Stewart]

I have a question about indexing.

a=randi(9,5)

[b i]=sort(a)

c=a(i)

I would think that c should be the same as b, but it is not. 

The index array i has all the correct information in it as can be seen with

for k=1:columns(a)

w(:,k)=a(i(:,k),k);

endfor

now b-w is equal to 0

Is there  some technical reason that if you try and use the index array i on an matrix 

of the same dimensions, that it can't work?

I would think that it should apply each col of the i to a  in a(i)

as I did in the loop.

I know it can be vectorized:

 a(sub2ind (size(a), i, repmat(1:4, rows(a), 1)))

 a(i+(0:columns(a)-1)*rows(a))

but I just think that octave should be smart enough to just do a(i)

Doug

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DAS