Re: Nesting functional commands
- To: mathgroup at smc.vnet.net
- Subject: [mg102898] Re: [mg102875] Nesting functional commands
- From: Patrick Scheibe <pscheibe at trm.uni-leipzig.de>
- Date: Wed, 2 Sep 2009 03:59:25 -0400 (EDT)
- References: <200909010751.DAA18675@smc.vnet.net>
Hi,
in this case it is easy. Just "say" how you want it with braces
A = {1, 2, 3, 4};
Select[(3*# & /@ A), (# < 7 &)]
in other examples this would not work. Then you have the chance to use
Function[{x,y,..},...] and it gets clear to Mathematica.
Cheers
Patrick
On Tue, 2009-09-01 at 03:51 -0400, Erin Noel wrote:
> Hi,
>
> So how would you go about nesting a functional command inside of another
> functional command? For example, say A={1,2,3,4}, then 3*#&/@A = {3,6,9,12}.
> No problem. But then what if, within that vector {3,6,9,12}, I wanted to use
> the Select command to choose elements less than, say 7. The command
> Select[3*#&/@A,#<7&] doesn't work because, as far as I can tell, Mathematica
> doesn't know which "#" belongs to Select and which "#" belongs to the &/@
> mapping over A. I know that I could define 3*#&/@A as a new variable and
> then use that new variable in the Select command, but is there any way to
> nest multiple commands in this way?
>
> Thanks a lot in advance,
> Erin
>
>
- References:
- Nesting functional commands
- From: Erin Noel <enoel2@gmail.com>
- Nesting functional commands