erlang
The Erlang distribution is a continuous distribution bounded on the
lower side. It is a special case of the Gamma distribution where the
parameter, m, is restricted to a positive integer. As such, the Erlang
distribution has no region where F(x) tends to infinity at the minimum
value of x [m<1], but does have a special case at m=1, where it
reduces to the Exponential distribution.
The Erlang distribution has been used extensively in reliability and in
queuing theory, thus in discrete event simulation, because it can be
viewed as the sum of m exponentially distributed random variables, each
with mean beta.
Samples

erlang(double
beta,
int m, double min)

Description
Generates a sample of the Erlang distribution.
Parameters
Name 
Type 
Description 
beta 
double 
the scale
factor > 0 
m 
int 
the
shape factor (positive integer) 
min 
double 
the
minimum
x value 
Result
Type 
Description 
double 
the
generated sample 

erlang(double
beta, int m)

Description
Generates a sample of the Erlang distribution with min set
to
0. Is equivalent to erlang(beta, m, 0).
Parameters
Name 
Type 
Description 
beta 
double 
the scale
factor > 0 
m 
int 
the
shape factor (positive integer) 
Result
Type 
Description 
double 
the
generated sample 

erlang(double
beta,
int m, double min, java.util.Random r)

Description
Generates a sample of the Erlang distribution using the
specified random number generator.
Parameters
Name 
Type 
Description 
beta 
double 
the scale
factor > 0 
m 
int 
the
shape factor (positive integer) 
min 
double 
the
minimum
x value 
r 
java.util.Random 
the random
number generator 
Result
Type 
Description 
double 
the
generated sample 