rpwenroll {OneArmTTE}

Generate Piecewise Exponential Enrollment

Description

Generate Piecewise Exponential Enrollment

Usage

rpwenroll(n = NULL, enrollRates = tibble(duration = c(1, 2), rate = c(2, 5)))

Arguments

n

Number of observations. Default of NULL yields random enrollment size.

enrollRates

A tibble containing period duration (duration) and enrollment rate (rate) for specified enrollment periods. If necessary, last period will be extended to ensure enrollment of specified n.

Value

A vector of random enrollment times following piecewise exponential distribution.

Examples

# piecewise uniform (piecewise exponential inter-arrival times) for 10k patients enrollment
# enrollment rates of 5 for time 0-100, 15 for 100-300, and 30 thereafter
x <- rpwenroll(n=10000, enrollRates=tibble::tibble(rate = c(5, 15, 30), duration = c(100,200,100)))
plot(x,1:10000,
     main="Piecewise uniform enrollment simulation",xlab="Time",
     ylab="Enrollment")
# exponential enrollment
x <- rpwenroll(10000, enrollRates=tibble::tibble(rate = .03, duration = 1))
plot(x,1:10000,main="Simulated exponential inter-arrival times",
     xlab="Time",ylab="Enrollment")