CoxPhLb (version 1.2.0)

coxphlb.phtest.plot: Graphical Test of the Proportional Hazards Assumption of Covariates in Cox Model with Right-Censored Length-Biased Data

Description

Returns a plot of the cumulative sums of mean zero stochastic processes.

Usage

coxphlb.phtest.plot(x, n.plot = 20, seed.n = round(runif(1,1,1e09)))

Arguments

x

The result of the coxphlb.phtest function.

n.plot

The number of randomly selected realizations. Default is 20.

seed.n

An integer specifying seed number.

Details

The function returns a plot with the test statistics in a black line and 20 processes randomly sampled from the pool of resamples in grey lines. When the test statistics lie within the randomly sampled lines, it suggests that the model assumption is valid. A plot cannot be generated for the global test.

References

Lee, C.H., Ning, J., and Shen, Y. Model diagnostics for proportional hazards model with length-biased data. Lifetime Data Analysis 25(1), 79-96.

See Also

coxphlb, coxphlb.phtest

Examples

# NOT RUN {
# Fit a Cox model
fit.ee <- coxphlb(Surv(a, y, delta) ~ x1 + x2, data = ExampleData1,
                 method = "EE")

# Check the Proportional Hazards Assumption
ptest1 <- coxphlb.phtest(fit.ee, data = ExampleData1, spec.p = 2,
                        seed.n = 1234)
coxphlb.phtest.plot(ptest1, n.plot = 50, seed.n = 1234)			# display the plot
# }