Error of exponential t[3] must have positive value

[Sutene Mwambi]

Dear Quants

I am running this code which give me an error :Error of exponential t[3] must have positive value. However, when I change to a Weibull    t[i] ~ dweib(1,mu[i])I(t.cen[i],) it is running without a hitch. How can I solve the problem. A Wei(1,p)=Exp(p). Exponential does not like NA

model;

{

   for( i in 1 : N ) {

      t[i] ~ dexp(mu[i])I(t.cen[i],)

   }

   for( i in 1 : N ) {

      mu[i] <- exp(beta0 + beta1 * trt[i])

   }

   beta0 ~ dnorm( 0.0,1.0E-4)

   beta1 ~ dnorm( 0.0,1.0E-4)

}

list(N=255) 

 t[]         t.cen[]    trt[]  

   1.57808    0.00000     1

   1.48219    0.00000     1

  NA         7.33425     0 

   2.23288    0.00000     0

    NA          9.38356     1 

   3.27671    0.00000     0

    NA          9.64384     0 

   1.66575    0.00000     1

END

list(beta0 =0, beta1 = 0)

list(beta0 = -2.5, beta1 = -2.5)

list(beta0 =2.5, beta1 = 2.5)