negLL_function: Gompertz Negative Log Likelihood Function
Description
Computes negative log likelihood for optimizer
Usage
negLL_function(par, y, X, y.left, y.right, wt)
Value
The negative log likelihood of parameter estimates given observed data
Arguments
- par
a vector of parameter estimates
- y
a vector of death ages
- X
a model matrix
- y.left
left truncation age
- y.right
right truncation age
- wt
weight