Re: Function argument
- To: mathgroup at smc.vnet.net
- Subject: [mg66991] Re: Function argument
- From: Helen Read <hpr at together.net>
- Date: Tue, 6 Jun 2006 06:27:55 -0400 (EDT)
- References: <e60o3q$g5s$1@smc.vnet.net>
- Reply-to: read at math.uvm.edu
- Sender: owner-wri-mathgroup at wolfram.com
Bonny wrote:
> I would like to define a function g that evaluates another function f at a
> given value. That is,
>
> g[a, f[x]] := f[a]
>
> For example, I might want the function f[x]=ax^2+bx+c to be evaluated at x=1
> and get the result a+b+c. That is,
>
> g[1, ax^2+bx+c] should evaluate to a+b+c.
Presumably you mean a x^2+b x + c, right? (Note the spaces between a and
x^2, and between b and x).
> Again, I might want the function f[x]=Sin[x] to be evaluated at x=pi and get
You mean x=Pi, right?
> the result 0. That is,
>
> g[pi, Sin[x]] should evaluate to 0.
>
> Is there a way to accomplish this in Mathematica? Any help would be
> appreciated.
g[a_,f_]:=f/.{x->a}
will do what you want.
--
Helen Read
University of Vermont