D_weight_1 function

The first derivative of the D-optimality criterion w.r.t the model parameters

The first derivative of the D-optimality criterion with respect to the model parameters. This is a sub-function of D_weight to run one iteration of Newton-Raphson method.

D_weight_1(q, W, T1, T2, T3, X, inv1, inv2, inv3)

Arguments

• q: A numeric vector. User select weights defined in the function RDOPT
• W: A numeric vector. The first K-1 weights for a given design
• T1: A numeric vector. Model parameter values for the 3PL model
• T2: A numeric vector. Model parameter values for the 4PL model
• T3: A numeric vector. Model parameter values for the 5PL model
• X: A numeric vector. K dose levels for a given design
• inv1: A numeric matrix. Inverse information matrix for the 3PL model
• inv2: A numeric matrix. Inverse information matrix for the 4PL model
• inv3: A numeric matrix. Inverse information matrix for the 5PL model