Services & Resources / Wolfram Forums / MathGroup Archive
-----

MathGroup Archive 2009

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

Search the Archive

Re: setting discrete values for a function -- newbie

  • To: mathgroup at smc.vnet.net
  • Subject: [mg97644] Re: setting discrete values for a function -- newbie
  • From: Szabolcs Horvát <szhorvat at gmail.com>
  • Date: Tue, 17 Mar 2009 05:03:41 -0500 (EST)
  • References: <gpld42$qj5$1@smc.vnet.net>

Karsten W. wrote:
> Hello,
> 
> my task is to set some function values f[[a], f[b], ... to zero. Is
> there a nicer way to do this than this one:
> 
> Clear[f];
> args = Partition[{a,b,c}, 1];
> Apply[(f[#] = 0 )&, args, {1}];
> 
> Especially, can I avoid calling Partition?
> 

Map is what you need, not Apply:

(f[#] = 0) & /@ {a, b, c}

Or perhaps Scan is more appropriate (since we don't care about the 
return values):

Scan[(f[#] = 0) &, {a, b, c}]

Yet another possibility is

f[x_] /; MemberQ[{a, b, c}, x] = 0


  • Prev by Date: Re: Don't understand the response
  • Next by Date: Re: collecting certain powers
  • Previous by thread: Re: setting discrete values for a function -- newbie
  • Next by thread: PlotMarkers bug?