On Aug 3, 9:20 am, [EMAIL PROTECTED] wrote: > On Aug 2, 10:20 pm, "[EMAIL PROTECTED]" > > > > <[EMAIL PROTECTED]> wrote: > > A naive approach to rank ordering (handling ties as well) of nested > > lists may be accomplished via: > > > def rankLists(nestedList): > > def rankList(singleList): > > sortedList = list(singleList) > > sortedList.sort() > > return map(sortedList.index, singleList) > > return map(rankList, nestedList) > > > >>> unranked = [ [ 1, 2, 3, 4, 5 ], [ 3, 1, 5, 2, 4 ], [ -1.1, 2.2, > > 0, -1.1, 13 ] ] > > >>> print rankLists(unranked) > > > [[0, 1, 2, 3, 4], [2, 0, 4, 1, 3], [0, 3, 2, 0, 4]] > > > This works nicely when the dimensions of the nested list are small. > > It is slow when they are big. Can someone suggest a clever way to > > speed it up? > > Isn't there something wrong with the ordering? > > Pablo's answers are: > [ 1, 2, 3, 4, 5 ] == [0, 1, 2, 3, 4] correct > > [ 3, 1, 5, 2, 4 ] == [2, 0, 4, 1, 3] wrong? > > [ -1.1, 2.2, 0, -1.1, 13 ] == [0, 3, 2, 0, 4] wrong? > > Doing it in my head I get: > [ 3, 1, 5, 2, 4 ] == [ 1, 3, 0, 4, 2 ] > > [ -1.1, 2.2, 0, -1.1, 13 ] == [0, 3, 2, 1, 4] > > What gives? > > Did I misunderstand what "rank ordering (handling ties as well)" means?
There are many ways to skin this cat. I am considering the following approach: http://en.wikipedia.org/wiki/Rank_order#Standard_competition_ranking_.28.221224.22_ranking.29 -- http://mail.python.org/mailman/listinfo/python-list
