gompertz_fn {drda}  R Documentation 
Evaluate at a particular set of parameters the Gompertz function.
gompertz_fn(x, theta)
x 
numeric vector at which the Gompertz function is to be evaluated. 
theta 
numeric vector with the four parameters in the form

The Gompertz function f(x; theta)
is defined here as
alpha + (beta  alpha) exp(exp(eta * (x  phi)))
where theta = c(alpha, beta, eta, phi)
, alpha
is the lower horizontal
asymptote, beta > alpha
is the upper horizontal asymptote, eta
is the
steepness of the curve or growth rate, and phi
related to the function
value at x = 0
.
Numeric vector of the same length of x
with the values of the
Gompertz function.