Hi! I am reading from one data.frame and writing to antoher (that is: data- transfer...). Sometimes the value transferred is NA. I use the following line (i and j are well defined!): protocol$n.adjustments[i]<-protocol.adjustment$n.adjustments[j] I recieve this warning: invalid factor level, NAs generated in: [<-.factor(*tmp*, i, value = 0) What does this mean? The data.frames are read from files (and these files are saved with write.table(...,quote=FALSE). /Tomas Svensson WinNT, R 1.2.3 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
problem with levels in dataframes
2 messages · tomsv193@student.liu.se, Brian Ripley
On Mon, 2 Jul 2001 tomsv193 at student.liu.se wrote:
Hi! I am reading from one data.frame and writing to antoher (that is: data- transfer...). Sometimes the value transferred is NA. I use the following line (i and j are well defined!): protocol$n.adjustments[i]<-protocol.adjustment$n.adjustments[j] I recieve this warning: invalid factor level, NAs generated in: [<-.factor(*tmp*, i, value = 0) What does this mean? The data.frames are read from files (and these
It means protocol.adjustment$n.adjustments[j] is not a level existing in the factor protocol$n.adjustments, hence `invalid factor level'. You'll need to look at the details for yourself. Factors are designed to a fixed set of levels: you can't add to the levels by assignment like this. Brian
Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272860 (secr) Oxford OX1 3TG, UK Fax: +44 1865 272595 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._