Re: SortBy
- To: mathgroup at smc.vnet.net
- Subject: [mg118207] Re: SortBy
- From: Bill Rowe <readnews at sbcglobal.net>
- Date: Sat, 16 Apr 2011 07:35:52 -0400 (EDT)
On 4/15/11 at 3:56 AM, graser at gmail.com (graser) wrote:
>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, ??]
In[2]:= SortBy[ks, #[[2]] &]
Out[2]= {{500, 23, 5}, {40, 32, 1}, {300, 48, 2}, {120, 55, 7}}