Re: List Position
- To: mathgroup at smc.vnet.net
- Subject: [mg15769] Re: [mg15740] List Position
- From: Carl Woll <carlw at fermi.phys.washington.edu>
- Date: Sun, 7 Feb 1999 02:03:50 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
Harry,
The most straightforward solution is to use Position[], as in
Position[{{1},{1},{2},{8},{-3}}, a_ /; a<=0, 2, 1]
The syntax for Position is
Position[expr, pattern, levelspec, n]
where n tells mathematica to retrieve the first n positions which match
the pattern.
Carl Woll
Dept of Physics
U of Washington
On Fri, 5 Feb 1999, Harry flynn wrote:
> Can anyone tell me how I find the position in a list of the first value
> less than or equal to zero.
> For example, how can I get Mathematica to tell me that in the list
> {{1},{1},{2},{8},{-3}}
> that the first value of interest to me is position 5. Thanks in advance.
> Harry.
>
>