- #1
Hoplite
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I'm looking to model a system in which events are nearly perfectly randomly distributed but with a slight tendency for events to avoid each other. As you know, if the system were perfectly random, I could use a Poisson distribution. The probability distribution for the number of events would then be
## P(N) = \frac{\lambda^N e^{-\lambda}}{N!} . ##
And the Poisson distribution also allows us to determine the probability distributions for the locations of each event, since the Poisson distribution implies that individual events follow a uniform distribution. Hence, if every event occurs within ##(-L/2, L/2)##, and ##p(x)## is the probability distribution for the location of an individual event, then
## p(x) = \frac{1}{L}. ##
So, I'm looking for a modified Poisson distribution that allows the events to be slightly dispersed, rather than perfectly random and gives me equivalent equations for both ##P(N)## and ##p(x)##. I know of many that would give me an equation equivalent to ##P(N)##, but none that would give me an equivalent to ##p(x)##.
Naturally, any equation for ##p(x)## would have to take into account the locations of the other events, so it may only be able to produce an equation for ##p(x)## for a small number of events. For example, the first event to be placed within ##(-L/2, L/2)## has no preference for any location, so its probability density function would be
## p_1(x_1) = \frac{1}{L}. ##
The location of the second event, ##x_2##, however, would depend slightly on the location of the first, ##x_1##, and this is where it gets tricky. I don't know of any modified Poisson distribution that would allow me to determine the probability density function of the 2nd event, let alone the third or fourth.
Could anyone recommend a suitable distribution to use?
## P(N) = \frac{\lambda^N e^{-\lambda}}{N!} . ##
And the Poisson distribution also allows us to determine the probability distributions for the locations of each event, since the Poisson distribution implies that individual events follow a uniform distribution. Hence, if every event occurs within ##(-L/2, L/2)##, and ##p(x)## is the probability distribution for the location of an individual event, then
## p(x) = \frac{1}{L}. ##
So, I'm looking for a modified Poisson distribution that allows the events to be slightly dispersed, rather than perfectly random and gives me equivalent equations for both ##P(N)## and ##p(x)##. I know of many that would give me an equation equivalent to ##P(N)##, but none that would give me an equivalent to ##p(x)##.
Naturally, any equation for ##p(x)## would have to take into account the locations of the other events, so it may only be able to produce an equation for ##p(x)## for a small number of events. For example, the first event to be placed within ##(-L/2, L/2)## has no preference for any location, so its probability density function would be
## p_1(x_1) = \frac{1}{L}. ##
The location of the second event, ##x_2##, however, would depend slightly on the location of the first, ##x_1##, and this is where it gets tricky. I don't know of any modified Poisson distribution that would allow me to determine the probability density function of the 2nd event, let alone the third or fourth.
Could anyone recommend a suitable distribution to use?