| plot.cox.zph {survival} | R Documentation |
Displays a graph of the scaled Schoenfeld residuals, along with a smooth curve.
## S3 method for class 'cox.zph': plot(x, resid=TRUE, se=TRUE, df=4, nsmo=40, var, ...)
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.
|
df |
the degrees of freedom for the fitted natural spline, df=2 leads
to a linear fit.
|
nsmo |
number of points used to plot the fitted spline. |
var |
the set of variables for which plots are desired. By default, plots are
produced in turn for each variable of a model. Selection of a single variable
allows other features to be added to the plot, e.g., a horizontal line at
zero or a main title.
This has been superseded by a subscripting method; see the example below. |
... |
additional arguments passed to the plot function.
|
a plot is produced on the current graphics device.
data(veteran)
vfit <- coxph(Surv(time,status) ~ trt + factor(celltype) +
karno + age, data=veteran, x=TRUE)
temp <- cox.zph(vfit)
plot(temp, var=5) # Look at Karnofsy score, old way of doing plot
plot(temp[5]) # New way with subscripting
abline(0, 0, lty=3)
# Add the linear fit as well
abline(lm(temp$y[,5] ~ temp$x)$coefficients, lty=4, col=3)
title(main="VA Lung Study")