Anthony - It seems just possible that the difficulty may have nothing to do with nlme() or any other data analysis. The graph you describe could result if one of the y-values was five time as large as any of the others. This could result from an error in reading the data input file, a missing decimal point somewhere, etc.
In order to diagnose this, do range(data$y) (assuming that you are plotting a data frame named "data" with a column named "y"), then do data[ data$y == max(data$y), ] to look at just the offending row(s). Another possibility is that somehow you are setting "ylim" in the plotting command, but I assume you've excluded that one already. HTH - tom blackwell - u michigan medical school - ann arbor - On Thu, 20 Nov 2003, anthony staines wrote: > Hi, > I would be grateful for help with a problem which is irritating me. > I am quite sure that I am doing something stupid, but I can't see what it > is. > > I am running R 1.7 on Windows 2000. The graphics device is the PC screen. > > The graphics from the nlme demonstration in Bates an Pinheiro's manual work > just as advertised. The CO2 data and the Orthodont data dsiplay > beautifully.(plot(Orthodont, outer=true, key=false) However. when I try to > analyse a data set of my own, of about 2,770 measurements on 293 women the > graphics go very peculiar. The graphics in the example from the manual fill > most of the vertical extent of the graphics device. My graphics are correct > horizontally, but are confined to about one-fifth of the vertical extent of > the graphics device. As a result they look odd, and are almost usless for > analysis. They do seem, however, to be the correct graphics (In this case > maternal weight against gestational age for two groups of women). > > I have read the manual for the lattice commands, and the nlme command, and > indeed for the plain plot command, but failed to get any ideas. Roughly, I > need to tell lattice to use the full vertical extent of the display device. > If it helps, I can e-mail the offending images to you individually on > request. > > Anthony Staines, > Public Health, > UCD > ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help