smalldd1 {Opt5PL}

Sub-function of the function D_weight_2

Description

This computes the second derivative of the D-optimality criterion with respect to the model parameters for a specified model.

Usage

smalldd1(T, x1, x2, xl, inv, order)

Arguments

T

A numeric vector. Model parameter values

x1

A numeric. ith dose level

x2

A numeric. jth dose level

xl

A numeric. last dose level

inv

A numeric matrix. Inverse information matrix

order

numeric. The number of model paraemters: 3, 4, 5 for the 3, 4, 5PL models respectively