Erlang | CPN Tools help |
Function for generating values from n-Erlang distributions | CPN ML |
erlang(n:int, r:real) : real
where n>=1
and r>0.0
. Returns a drawing from an n
-Erlang
distribution with intensity r
.
A drawing from an n
-Erlang distribution can be derived by addition of
n
drawings from a exponential distribution.
Raises Erlang
exception, if n
<1 or r
<=0.0.
Mean: | n/r |
Variance: | n/r^2 |
Density functions for n
-Erlang distributions:
erlang(100,50.0)
A shop gives each 100
th customer a present. The arrival time
between customers is exponentially distributed with intensity r=50.0
per hour. The sums of the arrival times between customers is Erlang
distributed with parameters n=100
and r=50.0
.