Re: Giving several functions the same argument

*To*: mathgroup at smc.vnet.net*Subject*: [mg109624] Re: Giving several functions the same argument*From*: Ingolf Dahl <ingolf.dahl at telia.com>*Date*: Sat, 8 May 2010 07:08:43 -0400 (EDT)

Hi Simon. Define backmap[funclist_, x__] := Apply[#1, {x}] & /@ funclist Then backmap[{f, g}, x] gives {f[x], g[x]} and backmap[{Sin[#1] &, Cos[#1] &}, x] gives {Sin[x], Cos[x]} and backmap[{Sin[#1] &, Cos[#1] &}, Pi/6] gives {1/2,Sqrt[3]/2} You might also do backmap[{f, g}, x, y] which gives {f[x, y], g[x, y]} Best regards Ingolf Dahl Sweden -----Original Message----- From: Simon Pearce [mailto:Simon.Pearce at nottingham.ac.uk] Sent: den 7 maj 2010 12:28 To: mathgroup at smc.vnet.net Subject: [mg109624] [mg109587] Giving several functions the same argument 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