Fisher exact test

FisherExactTest(a::Integer, b::Integer, c::Integer, d::Integer)

Perform Fisher’s exact test of the null hypothesis that the success probabilities a/c and b/d are equal, that is the odds ratio (a/c) / (b/d) is one, against the alternative hypothesis that they are not equal.

The contingency table is structured as:

  X1 X1
Y1 a b
Y2 c d


The print output contains the conditional maximum likelihood estimate of the odd-ratio rather than the sample odds ratio; it maximizes the likelihood given by Fisher’s non-central hypergeometric distribution.

Implements: pvalue, confint


  • Fay, M.P. Supplementary material to Confidence intervals that match Fisher’s exact or Blaker’s exact tests. Biostatistics, 0(0): 1-13, 2009.