Model Browser User's Guide

Morgan-Mercer-Flodin Model

The Morgan-Mercer-Flodin (MMF) growth model is defined by

where is the value of the upper asymptote, is the value of the lower asymptote, is a scaling parameter, and is a parameter that controls the location of the point of inflection for the curve. The point of inflection is located at

for

There is no point of inflection for < 1. All the MMF curves are sublogistic, in the sense that the point of inflection is always located below 50% growth (0.5). The following constraints apply to the fit coefficient values:

• > 0, > 0, > 0, > 0

• >

The response feature vector g is given by

Three Parameter Logistic Model

Four-Parameter Logistic Curve