M: Multiplier for first deriviative of log-likelihood of 2PL.

Description Usage Arguments Value

View source: R/IRF_functions.R

Description

Writing the derivative of the log-likelihood of the 2PL in theta for a single item as M * dIRF, this function computes (a matrix of values of) M, with dIRF being the first deriviative of the 2PL IRF. Called by functions that compute derivative of the log-likelihood.

Usage

1
M(resp, parms, theta)

Arguments

resp

a matrix or data.frame containing the binary item responses.

parms

a named list or data.frame with elements parms$alpha and parms$beta corresponding to the discrimination and difficulty parameters of the 2PL model, respectively.

theta

the latent trait.

Value

dim(resp)-matrix of multipliers.


peterhalpin/cirt documentation built on July 15, 2018, 12:42 p.m.