# Generalised logistic function (Richards' curve)

## Description

A logistic function or logistic curve is a common “S” shape (sigmoid curve) The generalized logistic curve or function, also known as Richards’ curve is a widely-used and flexible sigmoid function for growth modelling, extending the logistic function.

Related formulas## Variables

Y(t) | weight, height, size etc. (dimensionless) |

A | the lower asymptote (dimensionless) |

K | the upper asymptote. If A=0 then K is called the carrying capacity (dimensionless) |

Q | depends on the value Y(0) (dimensionless) |

e | e |

B | the growth rate (dimensionless) |

t | time (dimensionless) |

M | the time of maximum growth if Q=ν (dimensionless) |

v | ν>0 : affects near which asymptote maximum growth occurs. (dimensionless) |