# Physics307L F09:People/Mondragon/Poisson/Notebook/20071217

Still some planning and thinking

## what poisson_rnd(lambda, r, c) does

Octave's poisson_rnd(lambda, r, c) generates a matrix with r rows and c columns of random integers sampled from a Poisson distribution with parameter lambda, lambda being the parameter λ in the equation

$P(k;\lambda)=\frac{\lambda^k e^{-\lambda}}{k!}$

Or the Poisson probability mass distribution. k is an integer that could be in the matrix, and P(k;λ) is the probability that it is in the matrix.

Here is a sample of what it does:

octave:1> sample=poisson_rnd(4.793,10,12)
sample =

5   3   5   3   7   6   2   4   6   5  10   8
8   4  10   6   3   8   6   4   3   2   6   7
3   5   4   3   4   1   1   2   3   2   4   4
4   7   5   6  10   5   6   7   4   4   7   3
5   9   2   8   6   3   2   3   2   7   3   5
5   6   5   2   5   1   7   6   6   9   2   4
4   3   1   3   6   4   2   1   9   2   3   8
5   3   5   4   0   3   2   6   3   6   0   6
10   5   5   3   7   4   4   0   7   6   2   4
2   6   6   2   3   3   7   6   6   7   2   7



## plots

plot(sample) plots the columns of sample against the row index, which I guess could be useful later on, but not right now.