
 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.


 Internals

The probability density function (PDF) of a beta random
variable is
 \[ f(x) = x^(a-1) * (1-x)^(b-1) / B(a,b) \]
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
 betapdf.png
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 =
      0.4343    0.4220    0.3992    0.2727    0.2475


* FreeMat_Documentation
* Random_Number_Generation
* Generated on Thu Jul 25 2013 17:17:45 for FreeMat by
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