Re: [R] rpart for survival fits
When I plot a survival fit using rpart for the classification tree, for each node, there is a decimal based number above the event/total. I tried to see if it's the exponential ratio or logrithmics, neither seem to be the case. I'm wondering if anyone knows what they are. - It is an estimate of the event rate, using a Baysian shrinkage argument (#events +a) / (n +b) *c To understand how the constants a and b are chosen, you need to read the detailed documentation (as pointed out already by Brian R). The constant c is chosen to make the printed rate of the top node equal to 1. This last is done just to make it easier to scan the tree -- one can easily see that the rate is, say, 20% lower in some particular node than for the data set as a whole. Terry Therneau __ 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.
[R] rpart for survival fits
Hello Gurus: When I plot a survival fit using rpart for the classification tree, for each node, there is a decimal based number above the event/total. I tried to see if it's the exponential ratio or logrithmics, neither seem to be the case. I'm wondering if anyone knows what they are. Thanks, Karen _ Find hidden words, unscramble celebrity names, or try the ultimate crosswor[[elided Hotmail spam]] [[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.
Re: [R] rpart for survival fits
On Mon, 5 May 2008, Chang Liu wrote: Hello Gurus: When I plot a survival fit using rpart for the classification tree, I don't think that is a 'classification tree': no classification is going on. I will assume you called rpart() with a survival response. for each node, there is a decimal based number above the event/total. I tried to see if it's the exponential ratio or logrithmics, neither seem to be the case. I'm wondering if anyone knows what they are. Yes, I am sure the author knows. But to be precise, plotting the fit does not output those numbers, the text() method does. What it adds is the frame$yval component of the fit, the 'fitted value' according to ?rpart.object (which is printed when you print the fit). You really do need to read the documentation to understand what the fitted values are in this case. E.g. http://www.mayo.edu/hsr/techrpt/61.pdf Thanks, Karen __ 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. -- Brian D. Ripley, [EMAIL PROTECTED] 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 272866 (PA) Oxford OX1 3TG, UKFax: +44 1865 272595 __ 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.
