SurvTest {coin}R Documentation

Independent Two- and K-Sample Tests for Censored Data

Description

Usage

## S3 method for class 'formula':
surv_test(formula, data, subset = NULL,  weights = NULL, ...)
## S3 method for class 'IndependenceProblem':
surv_test(object, 
    alternative = c("two.sided", "less", "greater"),
    distribution = c("asympt", "approx", "exact"), ...)

Arguments

formula a formula of the form Surv(time, event) ~ x | block where time is a positive numeric variable denoting the survival time and event is a logical being TRUE when the event of interest was observed and FALSE in case of censoring. x is a factor with two or more levels giving the corresponding groups. block is an optional factor for stratification.
data an optional data frame containing the variables in the model formula.
subset an optional vector specifying a subset of observations to be used.
weights an optional formula of the form ~ w defining integer valued weights for the observations.
object an object of class IndependenceProblem.
alternative a character, the alternative hypothesis must be one of "two.sided" (default), "greater" or "less". You can specify just the initial letter.
distribution a character, the null distribution of the test statistic can be computed exactly or can be approximated by its asymptotic distribution (asympt) or via Monte-Carlo resampling (approx).
... further arguments to be passed to or from methods.

Details

The null hypothesis of the equality of the distribution of the survival functions in the groups induced by x is tested.

Value

An object inheriting from class IndependenceTest-class with methods show, statistic, expectation, covariance and pvalue. The null distribution can be inspected by pperm, dperm, qperm and support methods.

Examples


data(ocarcinoma, package = "coin")

surv_test(Surv(time, event) ~ stadium, data = ocarcinoma, 
             distribution = "exact")


[Package coin version 0.2-9 Index]