Internal fast log-rank test implementation

This is an internal implementation of right-censored logrank test for use within ic_logrank where many tests need to be performed efficiently for variance calculation.

Usage

cpp_logrank(time, event, group)

Arguments

time: Numeric vector of survival/censoring times.
event: Logical vector of event indicators (TRUE = event, FALSE = censored).
group: Integer vector of group labels, coded as consecutive integers (i.e. 1, 2, ...). This is not checked.

Value

An object of class "cpp_logrank", a list with components:

observed: Numeric vector of observed events per group.
expected: Numeric vector of expected events per group.
variance: Numeric variance matrix
n_by_group: Numeric vector of sample sizes per group.

Examples

set.seed(1992)
time  <- rexp(100)
event <- sample(c(TRUE, FALSE), 100, replace = TRUE)
group <- sample(1:2, 100, replace = TRUE)
cpp_logrank(time, event, group)
#> 
#> Log-rank test
#> Sample sizes by group:
#>  1  2 
#> 47 53 
#> 
#>          N Observed Expected     O-E
#> Group 1 47       27  25.6869  1.3131
#> Group 2 53       25  26.3131 -1.3131
#> 
#> Variance-covariance matrix:
#>          1        2
#> 1  12.5806 -12.5806
#> 2 -12.5806  12.5806