RANDEXP Generate Exponential Random Variable
Section:  Random Number Generation 
Usage
Generates a vector of exponential random variables with
the specified parameter.  The general syntax for its use is
   y = randexp(lambda)
where lambda is a vector containing the parameters for
the generated random variables.
Function Internals
The exponential random variable is usually associated with
the waiting time between events in a Poisson random process.
The PDF of an exponential random variable is:
Example
Here is an example of using the randexp function to generate
some exponentially distributed random variables
--> randexp(ones(1,6))
ans = 
    0.0608    0.0019    1.1266    0.2012    0.5079    3.4205