initrichards:
Function to generate initial values for parameter estimation
Description
The function receives time points, growth data, values for $A$, $\mu$ and $\lambda$ and returns a list object which entrys are used as initial values in the nonlinear fit procedure nls. In this type of model initial values for shape exponent $\nu$.
Usage
initrichards(time, y, A, mu, lambda)
Arguments
A
Maximum of the curve. If a vector is provided only the first entry is used.
mu
Maximum slope. If a vector is provided only the first entry is used.
lambda
Lag-phase. If a vector is provided only the first entry is used.
Value
- A
- Maximum of the curve.
- mu
- Maximum slope.
- lambda
- Lag-phase.
- addpar
- Shape exponent $\nu$.