Computes a confidence interval for a population Poisson rate. This function requires the number of occurences (f) of a specific event that were observed over a specific period of time (t).
ci.poisson(alpha, f, t)alpha value for 1-alpha confidence
number of event occurences
time period
Returns a 1-row matrix. The columns are:
Estimate - estimated Poisson rate
SE - recovered standard error
LL - lower limit of the confidence interval
UL - upper limit of the confidence interval
The time period (t) does not need to be an integer and can be expressed in any unit of time such as seconds, hours, or months. The occurances are assumed to be independent of one another and the unknown occurance rate is assumed to be constant over time.
Hahn GJ, Meeker WQ (1991). Statistical Intervals: A Guide for Practitioners. Wiley. ISBN 9780470316771, doi:10.1002/9780470316771 , http://dx.doi.org/10.1002/9780470316771.
ci.poisson(.05, 23, 5.25)
#> Estimate SE LL UL
#> 4.380952 0.9684952 2.777148 6.57358
# Should return:
# Estimate SE LL UL
# 4.380952 0.9684952 2.777148 6.57358