Re: Evaluation Question
- To: mathgroup at smc.vnet.net
- Subject: [mg76523] Re: Evaluation Question
- From: Szabolcs <szhorvat at gmail.com>
- Date: Wed, 23 May 2007 05:33:29 -0400 (EDT)
- Organization: University of Bergen
- References: <f2u57d$k2n$1@smc.vnet.net>
hoffmannick wrote:
> Can anyone help me solve the following problem?
>
> I have a function of 3 variables, let's say
> f[a_, b_, c_] = a + b + c
>
> Now I need to evaluate the function at some given points. To evaluate
> at a single point I would do
> f[0,0,1]
>
> For the point (0,0,1)
>
> Now here is the main question.
> I need to evaluate this function at the points (0,0,0) through (1,1,1)
> That would be the points:
> 0,0,0
> 0,0,1
> 0,1,0
> 0,1,1
> 1,0,0
> 1,0,1
> 1,1,0
> 1,1,1
>
> I'm testing these for approx 32 different functions. Is there an easy
> way that I can define the function and then have it test all the
> points for me? It will always be those finite points listed above.
>
> I looked into the mathematica documentation and it said how to do this
> with a function of a single variable, but it didn't say how to do it a
> function of more than one variable.
>
> I really appreciate your help
Use Apply[] at level 1 of the list of argument-triples (look up the
third argument of Apply in the docs).
Apply[f, IntegerDigits[Range[2^3]-1, 2, 3], 1]
or
f @@@ IntegerDigits[Range[2^3]-1, 2, 3]
If you have many functions, f, g, h etc., use
(# @@@ IntegerDigits[Range[2^3] - 1, 2, 3]) & /@ {f, g, h}
Or if you found out how to do it for a function of a single variable (I
think you mean Map[]), you could define f to be such a function:
f[{a_, b_, c_}] := a + b + c
Now you can use /@ (Map) instead of @@@ (Apply)
(# /@ IntegerDigits[Range[2^3] - 1, 2, 3]) & /@ {f, g, h}
Szabolcs