Generalised logistic curve

The generalised logistic (or Richard's) curve is a widely used and flexible function for growth modelling.

Y = A + { C \over (1 + T e^{-B (X - M)}) ^ {1 / T} }

where Y = weight, height, size etc., and X = time.

It has five parameters:

A
the lower asymptote;
C
the upper asymptote minus A;
M
the time of maximum growth;
B
the growth rate;
T
affects near which asymptote maximum growth occurs.

See also

See also: Generalised logistic curve, Logistic function