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rpf (version 0.3)

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

m
item model
param
item parameters
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.

See Also

The numDeriv package.