tapply and NA value
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
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