If mu = 1 (the default),
this function generates random integers which have mean and variance
equal to 1, but which do not have a Poisson distribution.
The random integers take the values \(0\), \(1\) and \(N\)
with probabilities \(1/N\), \((N-2)/(N-1)\) and \(1/(N(N-1))\)
respectively.
See Baddeley and Silverman (1984).
If mu is another positive number, the random integers will
have mean and variance equal to mu. They are obtained by
generating the
one-dimensional counterpart of the cell process and counting the
number of points in the interval from 0 to mu. The
maximum possible value of each random integer is N * ceiling(mu).