d11 function

Computing each element of the function DD_weight_1

This function computes each element of the vector function DD_weight_1 which is the first derivative of the Ds-optimality criterion with respect to the model parameters.

d11(T, x, xl, inv, inv1, order)

Arguments

• T: A numeric vector. Model parameter values
• x: A numeric. ith dose level for a given design
• xl: A numeric. last dose level for a given design
• inv: A numeric matrix. Inverse of the information matrix for the 5PL model
• inv1: A numeric matrix. Inverse of the information matrix for the 4PL model
• order: numeric. The number of model paraemters