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Groups > comp.soft-sys.math.mathematica > #1725

Re: SortBy

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Am 15.04.2011 09:56, schrieb graser:
> 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?
>

While there are functions First and Last, there is no Second and Third, 
but maybe that's an inexpensive possibility to increase the number of 
functions in the next version even more :-).

But you can use a pure function:

SortBy[KS, #[[2]] &]

hth,

albert

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SortBy graser <graser@gmail.com> - 2011-04-15 07:56 +0000
  Re: SortBy Peter Pein <petsie@dordos.net> - 2011-04-16 11:34 +0000
  Re: SortBy Albert Retey <awnl@gmx-topmail.de> - 2011-04-16 11:38 +0000
  Re: SortBy Peter Breitfeld <phbrf@t-online.de> - 2011-04-16 11:38 +0000
  Re: SortBy "Sjoerd C. de Vries" <sjoerd.c.devries@gmail.com> - 2011-04-16 11:39 +0000
  Re: SortBy Helen Read <readhpr@gmail.com> - 2011-04-16 11:32 +0000

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