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@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.