[R] performing function on data frame

[ONKELINX, Thierry]

Dear karin,

Try rescaler from the reshape package:

install.packages("reshape") 
library("reshape")
newDF <- apply(oldDF, 2, rescaler, type = "sd")

HTH,

Thierry

------------------------------------------------------------------------
----
ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek / Research Institute for Nature
and Forest
Cel biometrie, methodologie en kwaliteitszorg / Section biometrics,
methodology and quality assurance
Gaverstraat 4
9500 Geraardsbergen
Belgium 
tel. + 32 54/436 185
Thierry.Onkelinx at inbo.be 
www.inbo.be 

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than asking him to perform a post-mortem examination: he may be able to
say what the experiment died of.
~ Sir Ronald Aylmer Fisher

The plural of anecdote is not data.
~ Roger Brinner

The combination of some data and an aching desire for an answer does not
ensure that a reasonable answer can be extracted from a given body of
data.
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-----Oorspronkelijk bericht-----
Van: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org]
Namens Karin Lagesen
Verzonden: donderdag 16 april 2009 12:29
Aan: r-help at r-project.org
Onderwerp: Re: [R] performing function on data frame

David Hajage <dhajage.r at gmail.com> writes:

> Hi Karin,
>
> I'm not sure I understand... Is this what you want ?
>
> d$y - mean(d$y)/sd(d$y)




Yes, and also a bit no.

Each column in my data frame represents one data set. For every
element in this data set I want to know the z value for that
element. I.e: I want to create a new data frame from the old data
frame, where each element in the new data frame is

newDF[i,j] = oldDF[i,j] - mean(d[,j]) / sddev(d[,j])

I could, I think, iterate like this over the data frame, but I keep
thinking that one of the apply functions should be employed...

Karin
-- 
Karin Lagesen, Ph.D.
karin.lagesen at medisin.uio.no
http://folk.uio.no/karinlag

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