we don't have to as we make an accumulation before selection 
In the comments in the code i have the following example:
`[1 2 2] => [0.2, 0.6, 1.0]` But this might as wel be `[2 1 2] => [0.4 0.6 1.0]`. So sorting is not needed for that. I was to tired last night to be sure though so I left it with this comment, wat do you think? we'll have to sort at some point (for selection)