Re: Giving several functions the same argument
- To: mathgroup at smc.vnet.net
- Subject: [mg109605] Re: Giving several functions the same argument
- From: cinnabar <kolbasa.sapiens at gmail.com>
- Date: Sat, 8 May 2010 07:05:16 -0400 (EDT)
- References: <hs0pkd$dmm$1@smc.vnet.net>
On 7 =D0=BC=D0=B0=D0=B9, 12:22, Simon Pearce <Simon.Pea... 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 Hi, Simon The problem is you are applying a list to an argument, not a pure function Correct way is: In[1]:= {Sin[#], Cos[#]} &[x] Out[1]= {Sin[x], Cos[x]} i.e. making one pure function with a list of bodies Best Regards, Roman