Processing a list of lists
Say I have a master list made up of sub-lists that looks like this:
A 23 78
B 49 12
C 23 92
D 56 87
E 23 96
etc.
and I want to thin out repetitions in the second element of each list, so I get something like this:
A 23 78
B 49 12
D 56 87
How do I go about this? A further complication - how might I thin out repetitions in the second element based on the third element? For example, of the sub-lists with repeating second elements, I want to keep the one with the highest number in the third element, resulting in this:
B 49 12
D 56 87
E 23 96
The context is I'm playing around with a FluCoMa patch that slices a buffer, each slice gets assigned an identifier (an integer) and then mapped to x/y coordinates (floats). I'd like to round the coordinates, then filter out slices which have repeating x or y coordinates. Maybe based on slice length, so keep the longest/shortest? Or maybe based on nearby coordinates? I'm not sure yet, I have to figure out the processing part first.
the most simple way to compare all elements in a set against all other elements is brute force: have two counters running, one for A (1-8) and one for B (1-8, 1-8, 1-8, 1-8, 1-8, 1-8, 1-8, 1-8). (or optimize it a bit by excluding double combinations)
the actual process in the concrete case could look like this:
[route C]
zl slice 1]
[==]
when 1, then delete the C entry
..............................................
coll can do both for you
Ah ok, I've been playing with coll, but I don't know it very well. I didn't know about the sort message, very handy. I get the general idea behind Roman's route strategy, but I haven't quite figured out how to patch it yet. I think I'll keep playing with coll since all the info mainly comes from dictionaries.
my suggestion is meant as a general solution for "everything" which can be done with or to coll contents - of course, where they exist, the built-in functions of coll can be much easier to use.
I started to use part of your solution, insofar as I understand it, but I swapped route for coll and the counters for an uzi, then unpack the coll ouputs, compare them with == and... that's about as far as I got. It's a mess, haha. Which I guess is probably inevitable whatever the solution is. Oh well, as long as it works.