[R] more woes trying to convert a data.frame to a numerical matrix

[Dimitris Rizopoulos]

have a look at: ?as.numeric() and ?data.matrix().


I hope it helps.

Best,
Dimitris

----
Dimitris Rizopoulos
Ph.D. Student
Biostatistical Centre
School of Public Health
Catholic University of Leuven

Address: Kapucijnenvoer 35, Leuven, Belgium
Tel: +32/(0)16/336899
Fax: +32/(0)16/337015
Web: http://med.kuleuven.be/biostat/
     http://www.student.kuleuven.be/~m0390867/dimitris.htm


----- Original Message ----- 
From: "Andrew Yee" <andrewjyee at gmail.com>
To: <r-help at stat.math.ethz.ch>
Sent: Wednesday, May 16, 2007 2:10 PM
Subject: [R] more woes trying to convert a data.frame to a numerical 
matrix


>I have the following csv file:
>
> name,x,y,z
> category,delta,gamma,epsilon
> a,1,2,3
> b,4,5,6
> c,7,8,9
>
> I'd like to create a numeric matrix of just the numbers in this csv 
> dataset.
>
> I've tried the following program:
>
> sample.data <- read.csv("sample.csv")
> numerical.data <- as.matrix(sample.data[-1,-1])
>
> However, print(numerical.data) returns what appears to be a matrix 
> of
> characters:
>
>  x   y   z
> 2 "1" "2" "3"
> 3 "4" "5" "6"
> 4 "7" "8" "9"
>
> How do I force it to be numbers rather than characters?
>
> Thanks,
> Andrew
>
> [[alternative HTML version deleted]]
>
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> 


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