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randomnumbers.lognormal - Function

	Package	utility
	Module	mathematics
	Tool	randomnumbers

Generate random numbers with a log-normal distribution

Synopsis
lognormal(mean, variance, shape)

Description
The lognormal function will generate numbers that follow a log-normal distribution. I cannot find a mathematical definition of a probability density function that represents the output produced by this function, but it appears to be similar to a Ricean distribution, which is the sum of the square of two Gaussian random variables.

The mean and variance can be any positive number. The result will be floating point numbers in the range 0 < x < $\infty$. The shape can be either an integer or a vector of integers where all the values are greater than zero. The default value of one will produce a scalar output.

Arguments

mean	in	Mean of the distribution
		Allowed:	double
		Default:	1.0
variance	in	Variance of the distribution
		Allowed:	double
		Default:	1.0
shape	in	Shape of the output array
		Allowed:	integer or a vector of integers
		Default:	1

Returns
A floating point scalar or array.

Example

      include 'randomnumbers.g'
      rand := randomnumbers();
      numbers := rand.lognormal(shape=[2,5]);
      rand.done()

This example will calculate ten log-normal random numbers, storing the result in a two-dimensional array of shape [2,5]. The mean and variance both default to 1.0.