D_weight_1: The first derivative of the D-optimality criterion w.r.t the...
In Opt5PL: Optimal Designs for the 5-Parameter Logistic Model

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.

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

`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