Logistic Distribution

The logistic distribution is a symmetrical bell shaped distribution.  One of its applications is an alternative to the Normal distribution when a higher proportion of the of the population being modelled is distributed in the tails.  The table below shows a comparison of a Normal and Laplace distribution, each with a mean of zero and standard deviation of one.

	IQR	F(2.00)	Kurtosis
Normal	1.35	0.98	3.00
Logistic	1.21	0.97	4.20
Laplace	0.98	0.97	6.00

IQR is the interquartile range.

Profile

Parameters

Parameter	Description	Characteristics
Mean	Population mean	A float > -∞ and < ∞
stdev	Standard Deviation of Population	A float > 0

The logistic distribution is sometimes defined in terms of a location parameter (the mean) and a scale factor or standard deviation.  The relationship between the scale factor and the standard deviation is:

Functions

Properties