| Value | Meaning |
|---|---|
| direct | Direct |
| gamma | Gamma Incomplete function |
| approxNormal | Approximates poisson distribution with normal distribution. Generally a better approximation when lambda > 1000. |
| approxNormalContinuityCorrection | Approximates poisson distribution with normal distribution (including continuity correction). More accurate than PoissonAlgo.approxNormal. Generally a better approximation when lambda > 10. |
Algorithms used to calculate poisson dstribution.
PoissonAlgo.direct can be more time-consuming for large values of the number of events (k) or the rate of occurences (lambda). Additional algorithms are provided to the user to choose the trade-off between running time and accuracy.