## RANDBETA Beta Deviate Random Number Generator

Section: Random Number Generation

### Usage

Creates an array of beta random deviates based on the supplied two parameters. The general syntax for`randbeta`

is
y = randbeta(alpha, beta)

where `alpha`

and `beta`

are the two parameters of the
random deviate. There are three forms for calling `randbeta`

.
The first uses two vectors `alpha`

and `beta`

of the same
size, in which case the output `y`

is the same size as both
inputs, and each deviate uses the corresponding values of `alpha`

and `beta`

from the arguments. In the other forms, either
`alpha`

or `beta`

are scalars.

### Function Internals

The probability density function (PDF) of a beta random variable is

for `x`

between 0 and 1. The function `B(a,b)`

is defined so
that the integral of `f(x)`

is 1.

### Example

Here is a plot of the PDF of a beta random variable with`a=3`

,
`b=7`

.
--> a = 3; b = 7; --> x = (0:100)/100; t = x.^(a-1).*(1-x).^(b-1); --> t = t/(sum(t)*.01); --> plot(x,t);

which is plotted as

If we generate a few random deviates with these values,
we see they are distributed around the peak of roughly
`0.25`

.

--> randbeta(3*ones(1,5),7*ones(1,5)) ans = 0.2777 0.0642 0.3305 0.5259 0.4003