Hessian of log-likelihood method for wei_series_md_c1_c2_c3 model.

Returns the Hessian (second derivative matrix) of the log-likelihood for a Weibull series system. Computed numerically via the Jacobian of the score.

Usage

# S3 method for class 'wei_series_md_c1_c2_c3'
hess_loglik(model, ...)

Arguments

model

the likelihood model object

...

additional arguments (passed to returned function)

Value

hessian function that takes the following arguments:

• df: masked data frame

• par: parameter vector (shape1, scale1, shape2, scale2, ...)

• lifetime: system lifetime column name (default from model)

• lifetime_upper: interval upper bound column name (default from model)

• omega: observation type column name (default from model)

• candset: prefix of Boolean matrix encoding candidate sets