Re: SortBy
- To: mathgroup at smc.vnet.net
- Subject: [mg118192] Re: SortBy
- From: James Stein <mathgroup at stein.org>
- Date: Sat, 16 Apr 2011 07:33:06 -0400 (EDT)
The third basic example in the documentation for 'SortBy' shows the use of a
pure function, hence:
SortBy[KS, #[[2]] &]
On Fri, Apr 15, 2011 at 12:56 AM, graser <graser at gmail.com> wrote:
> Dear Mathematica group,
>
> I have a simple question for you.
>
> Let's say there is a list like
>
> KS = {{300, 48, 2}, {500, 23, 5}, {120, 55, 7}, {40, 32, 1}};
>
> I want to sort it by second element.
>
> I can use
>
> Sort[KS, #2[[2]] > #1[[2]] &]
>
> It gives out like
>
> {{500, 23, 5}, {40, 32, 1}, {300, 48, 2}, {120, 55, 7}}
>
> But if I want to use SortBy, how to do that?
>
> SortBy[KS, ??]
>
> Thanks!
>
>
>