Graphical Test of Proportional Hazards
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,
xlab="Time", ylab, lty=1:2, col=1, lwd=1, hr=FALSE, ...)x |
result of the |
resid |
a logical value, if |
se |
a logical value, if |
df |
the degrees of freedom for the fitted natural spline, |
nsmo |
number of points to use for the lines |
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 This has been superseded by a subscripting method; see the example below. |
hr |
if TRUE, label the y-axis using the estimated hazard ratio rather than the estimated coefficient. (The plot does not change, only the axis label.) |
xlab |
label for the x-axis of the plot |
ylab |
optional label for the y-axis of the plot. If missing a default label is provided. This can be a vector of labels. |
lty, col, lwd |
line type, color, and line width for the overlaid curve. Each of these can be vector of length 2, in which case the second element is used for the confidence interval. |
... |
additional graphical arguments passed to the |
a plot is produced on the current graphics device.
vfit <- coxph(Surv(time,status) ~ trt + factor(celltype) +
karno + age, data=veteran, x=TRUE)
temp <- cox.zph(vfit)
plot(temp, var=3) # Look at Karnofsy score, old way of doing plot
plot(temp[3]) # New way with subscripting
abline(0, 0, lty=3)
# Add the linear fit as well
abline(lm(temp$y[,3] ~ temp$x)$coefficients, lty=4, col=3)
title(main="VA Lung Study")Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.