logistic: Logistic curve function for nlme
Description
Logistic function used in fitting nlme curve for observations
Usage
logistic(dat, y, time, params = NULL, ...)
Arguments
- dat
subject data to be used
- y
outcome variable
- time
time variable
- params
NULL
unless user wants to specify starting parameters for gnls
- ...
just in case
Details
y ~ mini + (peak - mini) / (1 + exp(4 * slope * (cross - (time)) / (peak - mini)))