Graphical Test of Proportional Hazards

Tis is a ggplot version of plot.cox.zph. Displays a graph of the scaled Schoenfeld residuals, along with a smooth curve.

Usage

coxzphplot(x, resid = TRUE, se = TRUE, var = NULL, hr = FALSE, add.lm = FALSE)

Arguments

x

result of the cox.zph function.

resid

a logical value, if TRUE the residuals are included on the plot, as well as the smooth fit.

se

a logical value, if TRUE, confidence bands at two standard errors will be added.

var

The set of variables for which plots are desired. It can be integer or variable names

hr

logical If true, plot for hazard ratio, If false, plot for coefficients

add.lm

logical If true, add linear regression line

Value

A facetted ggplot

Examples

library(survival)
vfit <- coxph(Surv(time,status) ~ trt + factor(celltype) + karno + age, data=veteran, x=TRUE)
x <- cox.zph(vfit)
coxzphplot(x)

coxzphplot(x,var="karno",add.lm=TRUE)