motors {MASS} | R Documentation |
The motorette
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.
temp |
the temperature (degrees C) of the test |
time |
the time in hours to failure or censoring at 8064 hours (= 336 days). |
cens |
an indicator variable for death |
This data frame contains the following columns:
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.
library(survival5) data(motors) 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)) )