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