THE GENERALISED LOGISTIC CURVE

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

Y = A + C/((1 + T exp(-B(x-M))) ^ (1/T))

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

It has five parameters:
A, the lower asymptote;
C, the upper asymptote;
M, the time of maximum growth;
B, the growth rate;
T, near which asymptote maximum growth occurs.

You can explore, by means of a Java program, various settings of these parameters. Please be patient while an applet loads after clicking on 'explore'.

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Growth curve modelling 1.6.95 Page : 3 of 12