hi,

i am new using the multiindex library, and I need to do the following.
I have a set of d-dimensional points (e.g (3,5,8,9,5) is a 5-dimensional point), and I need to sort the points on each of the coordinates.

I want to store the points in a vector, and use multiindex to have all the points (vectors in this case) sorted in each of the coordinates.
E.g.

sorted by x:
x y z w
-----------
0 0 0 0
1 2 7 4
2 3 1 1
3 1 3 3
4 5 2 9

sorted by y:
0 0 0 0
3 1 3 3
1 2 7 4
2 3 1 1
4 5 2 9

etc...

would you mind pointing me in the right direction with an example of how to do it with multiindex library?

thanks