Logistic functions

The logisic function describe the classical logistic function,

logistic(x, yneg = -1, ypos = 1, lambda = 1, pow = 1)

logistic2(x, yneg = -1, ypos = 1, lambda = 1, pow = 1, yzer = 0)

Arguments

x	a numerical vector.
yneg	asymptotic values when x tends to -Inf.
ypos	asymptotic values when y tends to -Inf.
lambda	scalar coefficient.
pow	x exponent.
yzer	values (for logistic2 only).

Source

https://en.wikipedia.org/wiki/Logistic_functionwikipedia.org/wiki/Logistic_function

Value

A numeric vector.

Details

The classic logistic equation is:

$$f(x) = \frac{ypos-yneg}{1+e^{-\lambda x^{pow}}}$$

A slightly different version is:

$$f(x) = yneg + \frac{1}{\frac{1}{ypos-yneg}+(\frac{1}{yzer-yneg}-\frac{1}{ypos-yneg})e^{-\lambda x^{pow}}}$$

Functions

• logistic2: A slightly different logistic function.