km {asbio} | R Documentation |
Calculates survivorship for individuals in a population over time based on the method of Kaplan-Meier; cf. Pollock et al. (1989).
km(s, d, c, var = c("O", "G"), conf = 0.95)
s |
Vector of numbers of survivors in each age or time class. |
d |
Vector of the number of deaths in each age or time class. |
c |
Vector describing the number of censored individuals in each age or time class. |
var |
Type of procedure used to calculate variance in confidence intervals "O" = Oakes, "G" = Greenwood. |
conf |
Level of confidence for confidence interval calculations; 1 - P(type I error) |
Details for this index are given in Pollock et al. (1989).
Returns a list with the follwoing components
s.hat |
A vector of estimated survivorship probabilities from the 1st age class onward. |
Greenwood.Var |
The estimated Greenwood variance for each age class. |
Oakes.Var |
The estimated Oakes variance for each age class. |
CI |
Upper and lower confidence bound to the true survivorship. |
Ken Aho
Pollock, K. H., Winterstein, S. R., and Curtis, P. D. (1989) Survival analysis in telemetry studies: the staggered entry design. Journal of wildlife managment. 53(1):7-1.
##Example from Pollock (1989) r<-c(18,18,18,16,16,16,15,15,13,10,8,8,7) d<-c(0,0,2,0,0,1,0,1,1,1,0,0,0) c<-c(0,0,0,0,0,0,0,1,2,1,0,1,0) s<-r+d+c km(s,d,c)