motors {MASS} | R Documentation |
The motors
data frame has 40 rows and 3 columns. It describes an
accelerated life test at each of four temperatures of 10 motorettes,
and has rather discrete times.
motors
This data frame contains the following columns:
temp
time
cens
Kalbfleisch, J. D. and Prentice, R. L. (1980) The Statistical Analysis of Failure Time Data. New York: Wiley.
taken from
Nelson, W. D. and Hahn, G. J. (1972) Linear regression of a regression relationship from censored data. Part 1 – simple methods and their application. Technometrics, 14, 247–276.
Venables, W. N. and Ripley, B. D. (2002) Modern Applied Statistics with S. Fourth edition. Springer.
library(survival) plot(survfit(Surv(time, cens) ~ factor(temp), motors), conf.int = FALSE) # fit Weibull model motor.wei <- survreg(Surv(time, cens) ~ temp, motors) summary(motor.wei) # and predict at 130C unlist(predict(motor.wei, data.frame(temp=130), se.fit = TRUE)) motor.cox <- coxph(Surv(time, cens) ~ temp, motors) summary(motor.cox) # predict at temperature 200 plot(survfit(motor.cox, newdata = data.frame(temp=200), conf.type = "log-log")) summary( survfit(motor.cox, newdata = data.frame(temp=130)) )