First Derivative of Beta (xi1) (Internal)

Computes \(-z \times epn \times y \times H1(epn \times y)\), used in partial derivative w.r.t. beta.

Usage

xi1G.f(epn, z, y, H1)

Arguments

epn

Numeric, e.g. \(\exp(Z \beta)\).

z

Numeric or vector, representing the covariate(s).

y

Numeric, typically \(y[j]\) in iterative algorithms.

H1

A function, the first derivative of H.

Value

A numeric value for xi1.