Re: pure functions
- To: mathgroup at smc.vnet.net
- Subject: [mg23345] Re: pure functions
- From: Roland Franzius <Roland.Franzius at uos.de>
- Date: Thu, 4 May 2000 02:59:13 -0400 (EDT)
- Organization: RRZN - Newsserver Test
- References: <8eg4bn$g5i@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
One of \infty ways to accomplish your task is to Apply Plus to the inner Lists: Map[Apply[Plus,#]&,{a,b},{c,d}] {a+b,c+d} Your 2nd question is not quite clear to me. do you think of something like Select[{1, 2, 3, 4, 5, 6}, Function[{x}, x > 3]] ? Helge Andersson wrote: > > Hello, > > Of all the nice functions such as Map, Mapall, Thread, Apply .... I have > not been able to write a simple code to generate the following > procedure. > > I have a two dimensional list like > > li={{11,12,13,..},{21,22,23,...},{31,32,33,..},...} > > Since i like to use the pure function command I would like to map my > pure function with arguments #1,#2,#3,.... on all the sublists in li. > > Let me exemplify with a simple pure function that add to numbers. > (#1+#2)& > > if exli={{1,2},{3,4},{5,6},{7,8}} > > then I want to get the result > {3,7,11,15} > > One solution, but not allways suitable for me, is the following > > (#1+#2)&[Sequence @@ Transpose[exli]]. > > I want to get rid of the Transpose command and if possible also making > use of the /@ notation for Map. Since I have seen so many elegant > examples in the mailing lists I hope I can get something out of this. > > Finally, When using pure functions inside Mathematica defined functions > such as Select for instance, > Select[{1,2,3,4,5,6},#>3&] > why don't we need to specify the argument list after the &sign. I can > figure out that in this case the list sent to the Select command will be > used as argument list for the pure function but how does this work in > general. Which are the functions where this feature is possible? > > /Helge > > -- > ******************* > Helge Andersson > Oorganisk miljökemi > CTH > 412 96 Göteborg > > Tel. 031-772 8072 > Tel. Lab. 031-55 38 67 > Fax 031-772 28 53 -- Roland Franzius Theor. Physik FB Physik, Univ. Osnabrueck +++ exactly <<n>> lines of this message have value <<FALSE>> +++