Re: Evaluation Question
- To: mathgroup at smc.vnet.net
- Subject: [mg76483] Re: Evaluation Question
- From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
- Date: Wed, 23 May 2007 05:12:46 -0400 (EDT)
- Organization: The Open University, Milton Keynes, UK
- 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
Hi,
You can use either Map or Apply (depending on whether your function
accept a list of three arguments) over a list of lists. For instance,
In[1]:=
pts = {{0, 0, 0}, {0, 0, 1}, {0, 1, 0}, {0, 1, 1},
{1, 0, 0}, {1, 0, 1}, {1, 1, 0}, {1, 1, 1}};
(* Map *)
Clear[f]
f[{a_, b_, c_}] = a + b + c;
f /@ pts
(* Apply *)
Clear[f]
f[a_, b_, c_] = a + b + c;
Apply[f, pts, {1}]
Out[4]=
{0, 1, 1, 2, 1, 2, 2, 3}
Out[7]=
{0, 1, 1, 2, 1, 2, 2, 3}
Cheers,
Jean-Marc