[R] Cox model+ROCR

From: Eleni Christodoulou <elenichri_at_gmail.com>
Date: Mon, 03 Mar 2008 15:11:38 +0200


Dear list,

I am trying to build a cox model and then perform ROC analysis in order to retrieve some genes that are correlated with breast cancer. When I calculate the hazard score taking into account different numbers of genes and their coefficients ( I am trying to find the pest predictor number of genes), I retrieve from around 1 values (for few genes included ) to size of e+80 values (for many genes included).
I am using the "prediction" method from the ROCR package which takes as arguments the calculated scores and the true class scores. I really don't know what to compare my values with, because the only data that I have available are the time to relapse or last follow-up (months) and the relapse score (1=TRUE, 0=FALSE) of the patients. I have never performed ROC analysis before and I am a bit lost...
Any help with this is really very welcome!

Thank you all,
Eleni

        [[alternative HTML version deleted]]



R-help_at_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. Received on Mon 03 Mar 2008 - 13:25:49 GMT

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.2.0, at Mon 03 Mar 2008 - 13:30:18 GMT.

Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-help. Please read the posting guide before posting to the list.

list of date sections of archive