regDIF (version 1.1.1)

d_categorical_proxy: Partial derivatives for ordinal items using proxy data.

Description

Partial derivatives for ordinal items using proxy data.

Usage

d_categorical_proxy(
  parm,
  p_item,
  prox_data,
  pred_data,
  item_data_current,
  thr,
  cov,
  samp_size,
  num_responses_item,
  num_items
)

Value

a "list" of first and second partial derivatives for categorical item likelihood (to use with coordinate descent and univariate Newton-Raphson)

Arguments

parm

Item parameter being maximized.

p_item

Vector of item parameters.

prox_data

Vector of observed proxy scores.

pred_data

Matrix or dataframe of DIF and/or impact predictors.

item_data_current

Vector of current item responses.

thr

Threshold value being maximized.

cov

Covariate being maximized.

samp_size

Sample size in dataset.

num_responses_item

Number of responses for item.

num_items

Number of items in dataset.