I am sorry that this is another novice question. I am having trouble using "legend" with the survival curve plot from the survival package, and I wonder if it is because I have rescaled my plot. Here is the relevant segment of code:
plot(survfit(Surv(OS,Status)~shortishcr1),main='Overall Survival by
factor', + xlab='Years',ylab='% surviving',lty=c(1,2),xscale=365.25,yscale=100)
legend(5,80,c('Factor=1','Factor=2'),lty=c(1,2))
Here the variable OS is in days, but I want to plot it in years, so I scale it; likewise y is scaled to a percentage. I am trying to position the legend in the rescaled x and y values. Legend returns no error, but no legend appears on the plot. If I exclude the scaling altogether:
plot(survfit(Surv(OS,Status)~shortishcr1),main='Overall Survival by
factor', + xlab='Years',ylab='% surviving',lty=c(1,2),)
legend(1825,.8,c('Factor=1','Factor=2'),lty=c(1,2))
then the legend appears exactly as expected.
Using the unscaled version of the legend call with the scaled plot,
however, again no legend appears but no error is returned.
I suspect I am making some elementary mistake, but I just can't see it.
It is so elementary that I can't find a similar question in the
archives. Can someone help?
Here is my version information:
_
platform i386-pc-mingw32
arch i386
os mingw32
system i386, mingw32
status
major 2
minor 0.1
year 2004
month 11
day 15
language R
Rachel