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lognormal

Syntax

lognormal(mean, stdev)

Parameters

mean
Mean of the distribution.
stdev
Standard deviation of the distribution.

Returns

Returns a variate of a lognormal distribution.

Description

Returns a variate of a lognormal distribution. It is often used to model waiting times. The probability density function is:

\(\displaystyle p(x) = \frac{1}{x s \sqrt{2\pi}} e^{\frac{-\left(\log(x)-m\right)^2}{2s^2}}\)

where \(m\) is the mean of the log of the variable. \(s\) is the standard deviation of the log of the variable.

Examples

The following state will make entering agents collectively wait with a lognormal distribution(mean = 5, stdev = 2) of individual hourly wait times:

state Demo {
    wait(lognormal(5, 2))
    next(Excluded)
}

See Also