Re: How to reverse sign on the y's in a list of (x, y)'s?
- To: mathgroup at smc.vnet.net
- Subject: [mg61261] Re: How to reverse sign on the y's in a list of (x, y)'s?
- From: Helen Read <read at math.uvm.edu>
- Date: Fri, 14 Oct 2005 05:53:53 -0400 (EDT)
- References: <dikt77$4tm$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
sherifffruitfly at gmail.com wrote:
> Hi all,
>
> This is really dumb, but I just don't know how to do it...
>
> Import from excel gives me a list of ordered pairs, and I want the 2nd
> element of each pair to be of opposite sign. Sticking the negative sign
> in front of the entire Import statement reverses both the 1st and the
> 2nd elements (duh). How do I get just the second item to reverse sign?
v = your list of ordered pairs
Map[{#[[1]], -#[[2]]} &, v]
--
Helen Read
University of Vermont