Re: Evaluation Question
- To: mathgroup at smc.vnet.net
- Subject: [mg76464] Re: Evaluation Question
- From: Albert <awnl at arcor.net>
- Date: Wed, 23 May 2007 05:02:55 -0400 (EDT)
- 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
>
>
I think the easiest for this case is to use a special Form of Apply:
In[32]:=
f[a_, b_, c_] = a + b + c
Out[32]=
a + b + c
In[33]:=
points = {{0, 0, 0}, {1, 0, 0}, {0, 1, 0}}
Out[33]=
{{0, 0, 0}, {1, 0, 0}, {0, 1, 0}}
In[35]:=
Apply[f, points, {1}]
Out[35]=
{0, 1, 1}
that's a shortcut for it:
In[34]:=
f @@@ points
Out[34]=
{0, 1, 1}
this also works, but is more elaborate for multiple arguments:
In[40]:=
Map[Apply[f, #] &, points]
Out[40]=
{0, 1, 1}
In[41]:=
f @@@ points
Out[41]=
{0, 1, 1}
hth,
albert