Hello,

The concepts 'ordering’ and 'sorting’ in AIMMS pertain to one-dimensional sets. In AIMMS there is no predefined operator that can handle an example as given above by a single call; you will have to do some coding yourself. 

The remainder of this post illustrates one possible approach, perhaps there are also other approaches.

There are several remarks about the above code. 

1. The code handles the input from p_foo per slice.  In your example, by selecting a size and a car manufacturer, a slice is selected.
2. See line 5: for each slice, the number of elements is counted.
3. In the for loop of line 7 to line 26, one slice at a time is handled.
4. On line 10: A set is created that maps to the elements in the slice, number 1 .. n, n=number of elements in the slice.
5. Each element in the slice is given a number and copied to a one dimensional array p_onedim. Note that each element is handled individually.
6. As the data to be operated upon is now one-dimensional, the sort operator can be used.
   Important here: the set s_orderedPositions is declared to be "order by user”.
7. Based on the result of the sort operator, in line 25, the output parameter p_bar is filled.

The application that does this is attached to this post and a screenshot of the interface is shown below.

From the side panel, you can select size and car manufacturer.

With kind regards,

Chris