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The number of islands

The intensity of a Poisson point process an event in }. We can simulate a Poisson point process with given on an interval I as follows: Simulate the number of events N from . Form , and generate N i.i.d random numbers . Then are the points of a Poisson process with intensity .

Ex 2. Prove this.

Suppose the left ends of clones are a Poisson point process with intensity . And the clone lengths are i.i.d. with mean L. Let { t is uncovered }. Thin the original Poisson process back to by removing clones that do not overlap t. Thus a clone with left end at s is retained with probability , and the thinned process has intensity

So

Corollary.

Note that this result is the same as the exponential approximation of the exact calculation of in the case of constant clone length. It goes to 0 as .



Simon Cawley
Thu Apr 30 03:30:28 PDT 1998