R help - Mar 2007 - Standardization Range

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Hi sergio,
Sergio Della Franca wrote:
> Dear R-Helpers,
>
>
> I want to perform a standardization of a variable with range method.
>
> i.e.:
>
>  Standardization (range) ==> (var-min(var))/(max(var)-min(var))
>
>
> Do you konw how can i develop this?
>
>   
As you do ... but don't use var which is the name of the function to 
compute variance.

Try something like :

 > stdrange <- function(x) {(x-min(x))/(max(x)-min(x))}
 > var=1:10 # not a good idea, just for fun
 > stdrange(var)
 [1] 0.0000000 0.1111111 0.2222222 0.3333333 0.4444444 0.5555556 0.6666667
 [8] 0.7777778 0.8888889 1.0000000
> Thank you in advance.
>
>
> Sergio Della Franca
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
>
>   

-- 
St?phane DRAY (dray at biomserv.univ-lyon1.fr )
Laboratoire BBE-CNRS-UMR-5558, Univ. C. Bernard - Lyon I
43, Bd du 11 Novembre 1918, 69622 Villeurbanne Cedex, France
Tel: 33 4 72 43 27 57       Fax: 33 4 72 43 13 88
http://biomserv.univ-lyon1.fr/~dray/

you can still use scale() (as you have been told), look at the help 
page for more info, especially at the Arguments section, e.g.,


mat <- matrix(rnorm(100*10), 100, 10)

rng <- apply(mat, 2, range)
scale(mat, scale = rng[2, ] - rng[1, ])

or you could even use apply() directly, e.g.,

apply(mat, 2, function(x) (x - mean(x)) / diff(range(x)) )


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: "Sergio Della Franca" <sergio.della.franca at gmail.com>
To: <r-help at stat.math.ethz.ch>
Sent: Wednesday, March 28, 2007 11:00 AM
Subject: [R] Standardization Range

> Dear R-Helpers,
>
>
> I want to perform a standardization of a variable with range method.
>
> i.e.:
>
> Standardization (range) ==> (var-min(var))/(max(var)-min(var))
>
>
> Do you konw how can i develop this?
>
> Thank you in advance.
>
>
> Sergio Della Franca
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide 
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
> 

Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm