[Date Index] [Thread Index] [Author Index]

List of position-specifying functions

• To: mathgroup at smc.vnet.net
• Subject: [mg102351] List of position-specifying functions
• From: Ray Koopman <koopman at sfu.ca>
• Date: Thu, 6 Aug 2009 06:32:16 -0400 (EDT)

I have a list of distinct positive integers, such as

In[1]:= plist = {2, 5, 4, 6, 3};

I want to convert it to a list of position-specifying functions,
such as might be used as the second argument in SplitBy or GatherBy.
One way that works is:

In[2]:= plist /. p_Integer->(#[[p]]&)

Out[2]= { #1[[2]]&, #1[[5]]&, #1[[4]]&, #1[[6]]&, #1[[3]]& }

I've been trying to get the same thing using Map,
but I haven't been able to do it. Any suggestions?

• Follow-Ups:
  • Re: List of position-specifying functions
    • From: "Elton Kurt TeKolste" <tekolste@fastmail.us>
  • Re: List of position-specifying functions
    • From: DrMajorBob <btreat1@austin.rr.com>
  • Re: List of position-specifying functions
    • From: Andrzej Kozlowski <akoz@mimuw.edu.pl>
  • Re: List of position-specifying functions
    • From: Adriano Pascoletti <adriano.pascoletti@dimi.uniud.it>
  • Re: List of position-specifying functions
    • From: Leonid Shifrin <lshifr@gmail.com>