R help - Mar 2008 - colMeans in a data.frame with numeric and character data

Hi all,
 
I would like to know if it is posible by, someway, to get colMeans from
a data.frame with numeric as well as character data, dispersed all over
the object. Note that I would like to get colMeans neglecting character
data.
 
I am really in need of some function proceeding in that way…
 
All the best
 
Diogo André Alagador

	[[alternative HTML version deleted]]

try this:

dat <- data.frame(x = rnorm(10), y = rexp(10), z = letters[1:10])
colMeans(data.matrix(dat[sapply(dat, is.numeric)]))


I hope it helps.

Best,
Dimitris

----
Dimitris Rizopoulos
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


Quoting Diogo Andr? Alagador <dalagador at armail.pt>:
> Hi all,
>
> I would like to know if it is posible by, someway, to get colMeans from
> a data.frame with numeric as well as character data, dispersed all over
> the object. Note that I would like to get colMeans neglecting character
> data.
>
> I am really in need of some function proceeding in that way
>
> All the best
>
> Diogo Andr? Alagador
>
> 	[[alternative HTML version deleted]]
>
>


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

summaryBy in the doBy package can do that.  The builtin iris data
set has 4 numeric columns and one factor column:
> library(doBy)
> summaryBy(.~1, iris, fun = mean, keep = TRUE)
  Sepal.Length Sepal.Width Petal.Length Petal.Width
1     5.843333    3.057333        3.758    1.199333


On Thu, Mar 27, 2008 at 3:22 PM, Diogo Andr? Alagador
<dalagador at armail.pt> wrote:
> Hi all,
>
> I would like to know if it is posible by, someway, to get colMeans from
> a data.frame with numeric as well as character data, dispersed all over
> the object. Note that I would like to get colMeans neglecting character
> data.
>
> I am really in need of some function proceeding in that way?
>
> All the best
>
> Diogo Andr? Alagador
>
>        [[alternative HTML version deleted]]
>
>
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