This function returns a random integer from the geometric distribution, the number of independent trials with probability p until the first success. The probability distribution for geometric variates is,
for \(k \geq 1\). Note that the distribution begins with \(k=1\) with this definition. There is another convention in which the exponent \(k-1\) is replaced by \(k\).
This function computes the probability \(p(k)\) of obtaining \(k\) from a geometric distribution with probability parameter p, using the formula given above.
These functions compute the cumulative distribution functions \(P(k), Q(k)\) for the geometric distribution with parameter p.