I've been developing a Cox Proportional Hazards model, coxPHDC, using the survival package in R. I then tested the proportional hazards assumption with
cox.zph(coxPHDC) zph1 <- cox.zph(coxPHDC, transform = function(time) log(time)) plot(zph1)
As you can see there are non-proportional hazards with temperature in my results. My data is split between two temperatures, 320 C and 340 C, and there look to be two different groups in the graph. Even if these two groups aren't defined specifically along temperature I want to see which points in this graph are 320 C and which are 340 C. How can I code that?