[R] controlling plot range

[John Sorkin]

Windows XP 
R 2.5.0
I am trying to produce two plots that have the same range, i.e. x from 50 to 400 on both plots and y from 50 to 400 on both plots. (This will allow me to compare slopes). I have used the code below without success using usr (I have also used xaxp and yaxp but I am not including the code):

plot(tgNo26[,"TGh"],tgNo26[,"TGs"],usr=c(50,400,50,400))
plot(tgNo26[grep("CONTROL",tgNo26[,"PATIENT"]),"TGh"],
     tgNo26[grep("CONTROL",tgNo26[,"PATIENT"]),"TGs"],usr=c(50,400,50,400))

RESULT:
axes on first plot 50-400, y axis 50-350
axes on second plot 50-250 y axis 100-250


What am I doing wrong?

Thanks,
John

John Sorkin M.D., Ph.D.
Chief, Biostatistics and Informatics
University of Maryland School of Medicine Division of Gerontology
Baltimore VA Medical Center
10 North Greene Street
GRECC (BT/18/GR)
Baltimore, MD 21201-1524
(Phone) 410-605-7119
(Fax) 410-605-7913 (Please call phone number above prior to faxing)

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