rpf.dLL: Item parameter derivatives
Description
Evaluate the partial derivatives of the log likelihood with
respect to each parameter at where with weight.Usage
rpf.dLL(m, param, where, weight)
Arguments
where
location in the latent space
weight
per outcome weights (typically derived by observation)
Value
- first and second order partial derivatives of the log
likelihood evaluated at
where. For p parameters, the first
p values are the first derivative and the next p(p+1)/2 columns
are the lower triangle of the second derivative.
Details
It is not easy to write an example for this function. To evaluate
the derivative, you need to sum the derivatives across a
quadrature. You also need response outcome weights at each
quadrature point. It is not anticipated that this function will be
often used in R code. It's mainly to expose a C-level function for
occasional debugging.See Also
The numDeriv package.