Date: Jan 26, 2013 4:58 PM
Author: Bob Hanlon
Subject: Re: sorting?
lalista = {{0, 5}, {8, 8}, {2, 2}, {3, 5}, {1, 3}, {3, 9}};

SortBy[lalista, (Divide @@ #) + 10^-6*#[[2]] &] // Reverse

{{8, 8}, {2, 2}, {3, 5}, {3, 9}, {1, 3}, {0, 5}}

Bob Hanlon

On Sat, Jan 26, 2013 at 1:39 AM, Francisco Gutierrez

<fgutiers2002@yahoo.com> wrote:

>

> Friends:

> I have a large list of simple numerical lists, and I want to sort it using two criteria. in the simplest case, suppose the sublists are of length two, and

> that my first criterion is the quotient of part one by part two, and my second criterion is the size of part two (no zeros in part 2. I want to sort

> using the first criterion, and then break the ties using the second one.

> So for example if I had

> lalista={{0,5},{8,8},{2,2},{3,5},{1,3},{3,9}},

> the sorting should return

>

> {{8,8},{2,2},{3,5},{3,9},{1,3},{0,5}}

>

> Of course this can be done, but I wonder if it is a way to make this only with native Mathematica tools (wich is always far more efficient).

>

> Thanks for your help

>

> Francisco

>