Second Derivative of the loglogistic4 Model (Numerical)

Second Derivative of the loglogistic4 Model (Numerical)

Usage

d2x_loglogistic4(x, a, b, c, d, h = 1e-05)

Arguments

x

Numeric vector. Independent variable (typically log10-concentration).

a

Numeric scalar. Lower asymptote (baseline response).

b

Numeric scalar. Scale parameter (\(b > 0\)); controls steepness.

c

Numeric scalar. Inflection-point location on the x-axis.

d

Numeric scalar. Upper asymptote (saturation response).

h

Step size. Default 1e-5.

Value

Numeric vector of d²y/dx² values.