Hi All,

Last time Jaroslav helped me a lot with a little trick but this time I am a little bit jammed.

I would like to get solved a simple thing again and I cannot find a fast solution to it.

I have a matrix as

m = [

1 2;

1 1;

2 3;

2 4 ];

I would like to make a unique of its first column but I would like to have the minimum of second column nearby.

So it would look like:

[ 1 1;

2 3 ]

This is something like SELECT first_col, min(second_col) FROM m GROUP BY first_col;

If I can be sure that the second nargout of unique() always points always to the last index of the same

selector item then the solution would be something like:

m = sort( m, 'descend' );

[u,i,j] = unique( m(:,1) );

m(i,:)

but

1) can I be sure about it?

2) what if I would want to make aggregate functions such as avg() or var()

Thanks a lot,

Levente

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