PWEALL (version 1.3.0.1)

rpwecx: Piecewise exponential distribution with crossover effect: random number generation

Description

This will generate random numbers according to the piecewise exponential distribution with crossover

Usage

rpwecx(nr=1,rate1=c(1,0.5),rate2=rate1,rate3=c(0.7,0.4),
rate4=rate2,rate5=rate2,tchange=c(0,1),type=1,rp2=0.5)

Value

r

random numbers for the event time

rx

random numbers for the crossover time

cxind

indicators for the crossover, the first column indicates whether crossover occurs, i.e. \(\code{rx}<\code{r}\). When type=3,4,5, the second column of cxind indicates whether it crosses to the arm with rate2

Arguments

nr

number of random numbers to be generated

rate1

piecewise constant event rate before crossover

rate2

piecewise constant event rate after crossover

rate3

piecewise constant event rate for crossover

rate4

additional piecewise constant event rate for more complex crossover

rate5

additional piecewise constant event rate for more complex crossover

tchange

a strictly increasing sequence of time points starting from zero at which event rate changes. The first element of tchange must be zero. The above rates rate1 to rate6 and tchange must have the same length.

type

type of crossover, 1=markov, 2=semi-markov, 3=hybrid

rp2

re-randomization probability to receive the rescue treatment when semi-markov crossover occurs. When it happens, the overall hazard will be pi2*r2(t-s)+(1-pi2)*r4(t), where r2 is the hazard for the semi-markov rescue treatment and r4 is hazard for the markov rescue treatment.

Author

Xiaodong Luo

Details

More details

References

Luo et al. (2018) Design and monitoring of survival trials in complex scenarios, Statistics in Medicine <doi: https://doi.org/10.1002/sim.7975>.

See Also

rpwe

Examples

r1<-c(0.6,0.3)
r2<-c(0.6,0.6)
r3<-c(0.1,0.2)
r4<-c(0.5,0.4)
r5<-c(0.4,0.5)
pwecxr<-rpwecx(nr=10,rate1=r1,rate2=r2,rate3=r3,rate4=r4,rate5=r5,tchange=c(0,1),type=1)
pwecxr$r