       Re: "vector" Map[] / functional outer product?

• To: mathgroup at smc.vnet.net
• Subject: [mg83762] Re: "vector" Map[] / functional outer product?
• From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
• Date: Fri, 30 Nov 2007 05:13:14 -0500 (EST)
• Organization: The Open University, Milton Keynes, UK
• References: <fim8tq\$rmd\$1@smc.vnet.net>

```Mitch Murphy wrote:
> greetings,
>
> is there a simpler way to express
>
> 	{f@#,g@#}& /@ {a,b,c}
>
> 	-> {{f[a],g[a]},{f[b],g[b]},{f[c],g[c]}}
>
> ie. is there some mathematica function ??? such that
>
> 	{f,g} ??? {a,b,c}
>
> 	-> {{f[a],g[a]},{f[b],g[b]},{f[c],g[c]}}

<snip>

The following expression (In) will return the desired list without
the burden of passing explicitly any arguments to your functions.

In:= Outer[Compose, {f, g}, {a, b, c}] // Transpose

Out= {{f[a], g[a]}, {f[b], g[b]}, {f[c], g[c]}}

Note that if you want a nice infix notation, you could add some meaning
to a symbol without any built-in meaning, such as CirclePlus (On the
keyboard, you can enter the symbol CirclePlus as Esc c+ Esc --- i.e.
escape key followed by c followed by + followed by the escape key.)

In:= CirclePlus[f_, a_] := Transpose[Outer[Compose, f, a]]

In:= {f, g}\[CirclePlus]{a, b, c}

Out= {{f[a], g[a]}, {f[b], g[b]}, {f[c], g[c]}}

Regards,
--
Jean-Marc

```

• Prev by Date: Re: A problem with FindRoot
• Next by Date: Re: "vector" Map[] / functional outer product?
• Previous by thread: Re: "vector" Map[] / functional outer product?
• Next by thread: Re: "vector" Map[] / functional outer product?