Re: Data Extraction from List {{x1,y1}..{xn,yn}}where ##<x<##
- To: mathgroup@smc.vnet.net
- Subject: [mg11759] Re: Data Extraction from List {{x1,y1}..{xn,yn}}where ##<x<##
- From: bawolk@ucdavis.edu (Bruce Wolk)
- Date: Thu, 26 Mar 1998 03:09:28 -0500
- Organization: University of California, Davis
- References: <6f1p6l$ffn@smc.vnet.net>
On 21 Mar 1998 20:23:33 -0500, charles <koehlerc@execpc.com> wrote:
>Hello,
>
>How might I extract a range of {x,y}from a list of data, so that I can
>perform a linear fit between the point that meet the criterion of being
>bewteen x_n and x_m.
>
>In other words, fit a line to a part of the data that has #1<x<#2.
>
>I have attempted to use the Select function but it requires me to
>Flatten the data list first? And it results in giving me a list of just
>the x values not the {x,y} pairs.
>
>Any help is greatly appreciated.
>
>Thanks,
>
>Charles Koehler
>
>
Select will work, but there is a little trick. The following selects
those points with 3<x<5.
In[6]:=
a={{3,1},{4,2},{5,3},{-4,4}}
Out[6]=
{{3,1},{4,2},{5,3},{-4,4}}
In[7]:=
Select[a, 3<#[[1]]<5 &]
Out[7]=
{{4,2}}
Cheers,
Bruce