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MathGroup Archive 2001

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Re: select data in formatted datafiles

  • To: mathgroup at smc.vnet.net
  • Subject: [mg31394] Re: select data in formatted datafiles
  • From: "Carl T. Bergstrom" <cbergst at u.nospam.edu>
  • Date: Wed, 31 Oct 2001 19:59:17 -0500 (EST)
  • References: <9roe3k$pu0$1@smc.vnet.net>
  • Sender: owner-wri-mathgroup at wolfram.com

In article <9roe3k$pu0$1 at smc.vnet.net>, "Fabrice Gautheron"
<fabrice.gautheron at cern.ch> wrote:

> Hello,
> 
> I am interested to analyse data from a tab formatted datafile. I need to
> apply a function for one or two column(s) only over a total of 5
> columns. The ReadList command shows the format {data1, data2, data3,
> ...},{data1, data2,...}, ..
> 
> How to request only one or two columns (data2 column or data2 ar data5
> columns for example)?
> 

Fabrice,

To get an array with just the i-th column, transpose your data matrix, 
and then take the i-th entry.

E.g.

Where data is your matrix from ReadList,

column4= Transpose[data][[4]];

-------------------------------------
Carl T. Bergstrom                
Department of Zoology
University of Washington      
Replace nospam with washington to email
http://octavia.zoology.washington.edu            
-------------------------------------


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