inst/examples/isFitCoxPH_example.R

In gforge/Greg: Regression Helper Functions

# simulated data to use
set.seed(10)
ds <- data.frame(
  ftime = rexp(200),
  fstatus = sample(0:1, 200, replace = TRUE),
  x1 = runif(200),
  x2 = runif(200),
  x3 = runif(200)
)

library(survival)
library(rms)

dd <- datadist(ds)
options(datadist = "dd")

s <- Surv(ds$ftime, ds$fstatus == 1)
fit <- cph(s ~ x1 + x2 + x3, data = ds)

if (isFitCoxPH(fit)) {
  print("Correct, the cph is of cox PH hazard type")
}

fit <- coxph(s ~ x1 + x2 + x3, data = ds)
if (isFitCoxPH(fit)) {
  print("Correct, the coxph is of cox PH hazard type")
}

library(cmprsk)
set.seed(10)
ftime <- rexp(200)
fstatus <- sample(0:2, 200, replace = TRUE)
cov <- matrix(runif(600), nrow = 200)
dimnames(cov)[[2]] <- c("x1", "x2", "x3")
fit <- crr(ftime, fstatus, cov)

if (isFitCoxPH(fit)) {
  print(paste(
    "Correct, the competing risk regression is",
    "considered a type of cox regression",
    "since it has a Hazard Ratio"
  ))
}