Hi again, dear Dennis, i checked the spelling in Zuur et al. and they wrote it like i did. I tried your suggestion but now i have another warning message:
> D1<- data.frame(L.AREA= Loyn$L.AREA[Loyn$fGRAZE==1], fGraze = "1") Error in data.frame(L.AREA = Loyn$L.AREA[Loyn$fGRAZE == 1], fGraze = "1") : arguments imply differing number of rows: 0, 1 My aim i to display the predicted/fitted values of the different slopes for a factor in a plot. I tried different ways for my own data and when i found this solution i was happy, but even the provided solution with the provided dataset do not work... aaaahhhhh. Any ideas?? First i thought i had a problem with missing values, but in the Zuur data are no missing values. Heike Am 3/3/2011 18:51, schrieb Dennis Murphy: > Hi: > > You need the second variable in D1 to be named fGRAZE - the variable > names in the newdata data frame (D1) have to be the same as the > variable names on the RHS of the model formula, in this case L.AREA > and fGRAZE. > > HTH, > Dennis > > On Thu, Mar 3, 2011 at 7:43 AM, Heike Schmitz <schmi...@uni-bremen.de > <mailto:schmi...@uni-bremen.de>> wrote: > > Dear R- Community, > > to learn i reanalysed some data provided and analysed by Zuur et. > al. in their book "Mixed effect models and Extensions in Ecology > with R". When i run the last command i get a warning message i > dont understand. > > > Loyn<- read.table(file = "loyn.txt",header = TRUE) > Loyn$L.AREA<- log10(Loyn$AREA) > fGRAZE <-factor(Loyn$GRAZE) > > M0<- lm(ABUND~ L.AREA + fGRAZE, data = Loyn) > summary(M0) > > plot(x = Loyn$L.AREA, y = Loyn$ABUND, > xlab = "Log transformed AREA", > ylab = "Bird Abundance") > > D1<- data.frame(L.AREA= Loyn$L.AREA[Loyn$GRAZE==1], fGraze = "1") > P1<- predict(M0,newdata = D1) > > Warning message: > Error in model.frame.default(Terms, newdata, na.action = > na.action, xlev = object$xlevels) : > variable lengths differ (found for 'fGRAZE') > In addition: Warning message: > 'newdata' had 13 rows but variable(s) found have 56 rows > > I hope anyone has an idea. > Thank you in advance. > Heike > > -- > Heike Schmitz- Diaspero > Population Ecology and Evolutionary Ecology Lab, FB2 > University of Bremen > Leobener Strasse, Nw2, Room B4050 > D-28359 Bremen > Germany > fon ++49-421-218-62937 > email: heike.schm...@uni-bremen.de > <mailto:heike.schm...@uni-bremen.de> > > http://www.popecol.uni-bremen.de > > ______________________________________________ > R-help@r-project.org <mailto:R-help@r-project.org> mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > > -- Heike Schmitz- Diaspero Population Ecology and Evolutionary Ecology Lab, FB2 University of Bremen Leobener Strasse, Nw2, Room B4050 D-28359 Bremen Germany fon ++49-421-218-62937 email: heike.schm...@uni-bremen.de http://www.popecol.uni-bremen.de [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
