Re: Position of element in a list
- To: mathgroup at smc.vnet.net
- Subject: [mg16378] Re: [mg16301] Position of element in a list
- From: "Tomas Garza" <tgarza at mail.internet.com.mx>
- Date: Thu, 11 Mar 1999 02:16:48 -0500
- Sender: owner-wri-mathgroup at wolfram.com
Roger Mason wrote:
> I want to find the Position[] of negative elements in a list. The obvious
> methods do not work:
>
> Position[{-1, 3, -2, 1}, -_]
>
> and
>
> Position[{-1, 3, -2, 1}, -x_]
Roger,
Position[{-1,3,-2,1},x_/;x<0]
does the trick.
Tomas Garza
Mexico City