Re: Distinquishing #'s in nested pure functions
- To: mathgroup at smc.vnet.net
- Subject: [mg126283] Re: Distinquishing #'s in nested pure functions
- From: Murray Eisenberg <murray at math.umass.edu>
- Date: Sat, 28 Apr 2012 05:29:38 -0400 (EDT)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
- References: <201204260933.FAA05752@smc.vnet.net> <201204271048.GAA20037@smc.vnet.net>
- Reply-to: murray at math.umass.edu
The symbol # is an abbreviation for #1. You can have #1, #2, etc.
And actually, #1, #2, etc., are in turn abbreviations for the FullForm
names Slot[1], Slot[2], etc.
On 4/27/12 6:48 AM, Dave Snead wrote:
> Hi,
>
> Is there a way to distinguish the #'s in nested pure functions?
>
> As a simple example:
>
> f[x_, y_] := x - y
>
> Select[{1, 2, 3}, (f[#, #]& /@ {-1, -2, -3}) == {3, 4, 5}&]
>
> I want the 1st # to correspond with the outer& (the equal)
> and the 2nd # with the inner& (the map)
> The answer in this example should by {2}
> (of course, the statement as written above does not do the job)
>
> Can Mathematica distinguish these #'s?
>
> Thanks in advance,
> Dave Snead
>
>
--
Murray Eisenberg murray at math.umass.edu
Mathematics & Statistics Dept.
Lederle Graduate Research Tower phone 413 549-1020 (H)
University of Massachusetts 413 545-2859 (W)
710 North Pleasant Street fax 413 545-1801
Amherst, MA 01003-9305
- References:
- NonlinearModelFit and Complex Data
- From: Maria <rouelli@gmail.com>
- Distinquishing #'s in nested pure functions
- From: "Dave Snead" <dsnead6@charter.net>
- NonlinearModelFit and Complex Data