Re: Part
- Subject: [mg2895] Re: Part
- From: wagner at bullwinkle.cs.Colorado.EDU (Dave Wagner)
- Date: 5 Jan 1996 03:47:19 -0600
- Approved: usenet@wri.com
- Distribution: local
- Newsgroups: wri.mathgroup
- Organization: University of Colorado, Boulder
- Sender: mj at wri.com
In article <4cgrsc$im4 at dragonfly.wri.com>,
Hans Steffani <hans.steffani at e-technik.tu-chemnitz.de> wrote:
>w={{1,2,3},{4,5,6},{7,8,9}}
>npos={2,1}
>
>npos is the position of the element I need.
>
>w[[npos]]
>
>does not work, as it returns the second and the first
>line.
This same question came up a couple of weeks ago. You want
to use:
w[[Sequence @@ npos]]
Sequence is an undocumented function that obliterates the head
of whatever it is applied to. In this case, it obliterates the
List wrapper, leaving a sequence of two integers.
Dave Wagner
Principia Consulting
(303) 786-8371
dbwagner at princon.com
http://www.princon.com/princon