Re: Re: joining lists.
- To: mathgroup at smc.vnet.net
- Subject: [mg23838] Re: [mg23788] Re: joining lists.
- From: Andrzej Kozlowski <andrzej at tuins.ac.jp>
- Date: Mon, 12 Jun 2000 01:17:31 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
on 00.6.10 3:59 PM, Otto Linsuain at linsuain+ at andrew.cmu.edu wrote:
>
> Thanks to all that replied. Yes, I was definitely missing the obvious
> solution:
>
> {#1,#2} & [list1,list2] produces {list1,list2} without the unnecessary
> Join[{list1},{list2}].
>
> I was glad to learn that {##} & can do the same with more than two
> lists. Otto.
>
Since I was responsible for that latter answer I guess I should now point
out the obvious: f[##] & is exactly the same as f, except that it will
always evaluate its arguments first. So if a function has a HoldAll,
HoldFirst or HoldRest attribute there will be a difference. Thus
Plot[Table[x^i, {i, 1, 2}], {x, -1, 1}] will produce and error message
while
Plot[##] &[Table[x^i, {i, 1, 2}], {x, -1, 1}]
will work (you can of course use Evaluate inside Plot instead).
However, this has no relevance at all in the case of List.
Andrzej
--
Andrzej Kozlowski
Toyama International University
JAPAN
http://platon.c.u-tokyo.ac.jp/andrzej/
http://sigma.tuins.ac.jp/