sindex {prodlim} | R Documentation |
Returns an index of positions. Intended for evaluating a step function at selected times. The function counts how many elements of a vector, e.g. the jump times of the step function, are smaller or equal to the elements in a second vector, e.g. the times where the step function should be evaluated.
sindex(jump.times, eval.times,comp="smaller",strict=FALSE)
jump.times |
Numeric vector: e.g. the unique jump times of a step function. |
eval.times |
Numeric vector: e.g. the times where the step function should be evaluated |
strict |
If TRUE make the comparison of jump times and eval times strict |
comp |
If "greater" count the number of jump times that are greater (greater or equal when strict==FALSE) than the eval times |
If all jump.times
are greater than a particular
eval.time
the sindex returns 0
. This must
be considered when sindex is used for subsetting, see the
Examples below.
Index of the same length as eval.times
containing the numbers
of the jump.times
that are smaller than or equal to
eval.times
.
Thomas A. Gerds tag@biostat.ku.dk
test <- list(time = c(1, 1,5,5,2,7,9), status = c(1,0,1,0,1,1,0)) fit <- prodlim(Hist(time,status)~1,data=test) jtimes <- fit$time etimes <- c(0,.5,2,8,10) fit$surv c(1,fit$surv)[1+sindex(jtimes,etimes)]