

   AAcccceelleerraatteedd LLiiffee TTeessttiinngg ooff MMoottoorreetttteess

   AArrgguummeennttss::

       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

   SSUUMMMMAARRYY::

        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.

   DDAATTAA DDEESSCCRRIIPPTTIIOONN::

        This data frame contains the following columns:

   SSOOUURRCCEE::

        Kalbfleisch, J. D. and Prentice, R. L. (1980) The Sta-
        tistical 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.  Technomet-
        rics 14, 247-276.

   EExxaammpplleess::

        library(survival4)
        data(motors)
        attach(motors)
        plot(survfit(Surv(time, cens) ~ factor(temp)), conf.int=F)
        # fit Weibull model
        motor.wei <- survreg(Surv(time, cens) ~ temp)
        summary(motor.wei)
        # and predict at 130C
        at130 <- predict(motor.wei, data.frame(temp=130), se.fit=T)
        exp(at130$fit)

        motor.cox <- coxph(Surv(time, cens) ~ temp)
        summary(motor.cox)
        # predict at temperature 200
        plot( survfit(motor.cox, newdata=data.frame(temp=200)) )

