Hi, I'm writing for a little help. I have a dataframe with same NA value and I'd like to obtain the means of the value of a coloumn grouped by the levels of a factor coloumn of the datframe. I'm using the function "tapply" but I see that if only a NA value is present the result is NA. There is an option to have the correct result or I must use an other function? Thanks of all Leonardo -- Leonardo Lami lami at faunalia.it www.faunalia.it Via Colombo 3 - 51010 Massa e Cozzile (PT), Italy Tel: (+39)349-1310164 GPG key @: hkp://wwwkeys.pgp.net http://www.pgp.net/wwwkeys.html https://www.biglumber.com
you should look at the 'na.rm=FALSE' argument of '?mean()',
i.e.,
x <- rnorm(100); x[sample(100, 10)] <- NA
f <- sample(letters[1:5], 100, TRUE)
###############
tapply(x, f, mean)
tapply(x, f, mean, na.rm=TRUE)
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: +32/16/336899
Fax: +32/16/337015
Web: http://www.med.kuleuven.ac.be/biostat/
http://www.student.kuleuven.ac.be/~m0390867/dimitris.htm
----- Original Message -----
From: "Leonardo Lami" <lami at faunalia.it>
To: <r-help at stat.math.ethz.ch>
Sent: Friday, March 25, 2005 10:35 AM
Subject: [R] tapply and NA value
> Hi,
> I'm writing for a little help.
> I have a dataframe with same NA value and I'd like to obtain the
> means of the
> value of a coloumn grouped by the levels of a factor coloumn of the
> datframe.
> I'm using the function "tapply" but I see that if only a NA
value is
> present
> the result is NA.
> There is an option to have the correct result or I must use an other
> function?
>
> Thanks of all
> Leonardo
> --
> Leonardo Lami
> lami at faunalia.it www.faunalia.it
> Via Colombo 3 - 51010 Massa e Cozzile (PT), Italy Tel:
> (+39)349-1310164
> GPG key @: hkp://wwwkeys.pgp.net http://www.pgp.net/wwwkeys.html
> https://www.biglumber.com
>
> ______________________________________________
> 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
>
I am not really sure what you mean. If I understand you correctly, than all ylu have to do is to give additiona parameter to tapply, na.rm=TRUE, tapply(...., na.rm=TRUE) However as I already said, I'm not sure what you did and what is the problem. Plese provide the code that did not work, possibly with a workable example, as the posting guide suggests: "PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html" I hope this helps in anyway, Ales Ziberna ----- Original Message ----- From: "Leonardo Lami" <lami at faunalia.it> To: <r-help at stat.math.ethz.ch> Sent: Friday, March 25, 2005 10:35 AM Subject: [R] tapply and NA value> Hi, > I'm writing for a little help. > I have a dataframe with same NA value and I'd like to obtain the means of > the > value of a coloumn grouped by the levels of a factor coloumn of the > datframe. > I'm using the function "tapply" but I see that if only a NA value is > present > the result is NA. > There is an option to have the correct result or I must use an other > function? > > Thanks of all > Leonardo > -- > Leonardo Lami > lami at faunalia.it www.faunalia.it > Via Colombo 3 - 51010 Massa e Cozzile (PT), Italy Tel: (+39)349-1310164 > GPG key @: hkp://wwwkeys.pgp.net http://www.pgp.net/wwwkeys.html > https://www.biglumber.com > > ______________________________________________ > 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 > >