Re: Giving several functions the same argument
- To: mathgroup at smc.vnet.net
- Subject: [mg109614] Re: Giving several functions the same argument
- From: Leonid Shifrin <lshifr at gmail.com>
- Date: Sat, 8 May 2010 07:06:54 -0400 (EDT)
Hi Simon,
You are right, such a function does exist. Its name is Through:
In[9]:= functs = {Sin[#1] &, Cos[#1] &};
In[10]:= Through[functs[x]]
Out[10]= {Sin[x], Cos[x]}
Here is one more way to do this:
In[11]:= Map[#[x] &, functs]
Out[11]= {Sin[x], Cos[x]}
Regards,
Leonid
On Fri, May 7, 2010 at 2:28 PM, Simon Pearce
<Simon.Pearce at nottingham.ac.uk>wrote:
> Hi Mathgroup,
>
>
>
> I have a list of pure functions, which I wish to apply to the same
> argument. I can't seem to be able to thread the list of functions over
> the argument in a simple way, all the commands like Apply and Map etc
> take a single function. I can do it using Table and Part, but it seemed
> like there should be a simple command that I'm missing.
>
>
>
> For example:
>
>
>
> In[1]:= functs = {Sin[#1] &, Cos[#1] &};
>
>
>
> In[2]:= functs[x]
>
>
>
> Out[2]= {Sin[#1] &, Cos[#1] &}[x]
>
>
>
> I want to get the result {Sin[x],Cos[x]} out, without having to use
> something of the form:
>
>
>
> In[3]:= Table[functs[[i]][x], {i, 1, 2}]
>
>
>
> Out[3]= {Sin[x], Cos[x]}
>
>
>
> Which seems like it'd be less efficient when I try and use it on long
> lists of functions.
>
>
>
> Thanks,
>
> Simon
>
>