Re: List Question
- To: mathgroup at smc.vnet.net
- Subject: [mg67939] Re: List Question
- From: "James Gilmore" <james.gilmore at yale.edu>
- Date: Thu, 13 Jul 2006 06:54:07 -0400 (EDT)
- Organization: Yale University
- References: <e92e03$ljm$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hi Simon,
One can either use Take[] or write out the operation explicitly:
In[1]:=
list23 = {{x1, y1}, {x2, y2}, {x3, y3, z3}, {x4, y4}};
Map[{#1[[1]], #1[[2]]} &, list23]
Map[Take[#, 2] &, list23]
Out[2]=
{{x1, y1}, {x2, y2}, {x3, y3}, {x4, y4}}
Out[3]=
{{x1, y1}, {x2, y2}, {x3, y3}, {x4, y4}}
Writing out the operation is advantageous if you want to manipulate the data
set at the same time e.g. y->y^2, etc.
Cheers
James Gilmore
"Simon Bale" <simonjbale at gmail.com> wrote in message
news:e92e03$ljm$1 at smc.vnet.net...
> Hi,
>
> I have a list with the following structure:
>
> {{x1,y1},{x2,y2},{x3,y3,z3},{x4,y4}...}
>
> As you can see some of the data points have three elements. I would
> like to remove these z elements so that the list has a structure
> {{x1,y1},{x2,y2},{x3,y3},{x4,y4}...}. I'm not sure how to achieve this
> so any
> help is greatly appreciated.
>
> Regards, Simon Bale.
>