[ext_weibull_ex0] Extended Weibull Model
                              (Marshall-Olkin)


   
   [ext_weibull_ex1]
   
   model
   {
      for(i in 1 : N)
      {
      x[i] ~ dext.weib(alpha, lambda)
      }
      
      for (i in 1 : Ncen)
         {
            x.cen[i] ~ dext.weib(alpha, lambda)C(t.cen, )
         }
         
   # Prior distributions of the model parameters   
   
         alpha ~ dunif(0, 5.0)
         lambda~ dgamma(0.001, 0.001)
   }

The data set gives 100 observations on breaking stress of carbon fibres, Nichols and Padgett(2006).

Marshall, A. W. and Olkin, I. (1997). A new method for adding a parameter to a family of distributions with application to the exponential and Weibull families. Biometrika , 84(3) , 641-652.

Nichols, M.D. and W.J. Padgett, W.J. (2006). A bootstrap control chart for Weibull percentiles, Quality and Reliability Engineering International , 22, 141-151.


Data ( click to open )

Inits for chain 1       

Inits for chain 2     ( click to open )

Results
      mean   sd   MC_error   val2.5pc   median   val97.5pc   start   sample
   alpha   0.2934   0.02427   3.197E-4   0.2433   0.2942   0.3384   1001   50000
   lambda   141.5   111.7   1.387   31.88   110.7   430.3   1001   50000

   Dbar   Dhat   DIC   pD   
x   260.0   262.1   257.9   -2.096
x.cen   19.55   16.15   22.94   3.394
total   279.5   278.2   280.8   1.298

[ext_weibull_ex2]
[ext_weibull_ex3]

[ext_weibull_ex4]