KMW {survivalREC}

Kaplan-Meier weights

Description

This function returns a vector with the Kaplan-Meier weights.

Usage

KMW(time, status)

Arguments

time

Survival time of the process.

status

Censoring indicator of the survival time of the process; 0 if the survival time is censored and 1 otherwise.

Value

Vector with Kaplan-Meier weights.

Author(s)

Gustavo Soutinho and Luis Meira-Machado

References

E. Kaplan and P. Meier. Nonparametric estimation from incomplete observations. Journal of the American Statistical Association, 53:457-481, 1958.

Examples

data("bladder4state")

obj<- multidf(gap1=bladder4state$y1, event1=bladder4state$d1, 
              gap2=bladder4state$y2, status=bladder4state$d2, 
             size=bladder4state$size) 
             
obj2<-obj[[1]]
kmw <- KMW(time = obj2$time, status = obj2$status)
require(survival)
bladder.surv <- survfit(Surv(time, status) ~ 1, obj2)
times <- summary(bladder.surv)$time
surv <- summary(bladder.surv)$surv
nevent <- summary(bladder.surv)$n.event
p <- match(obj2$time, times)
kmw2 <- -diff(c(1, surv))/nevent
kmw2 <- kmw2[p]*obj2$status
kmw2[is.na(kmw2)] <- 0
all.equal(kmw, kmw2)