fishertest
              Fisher’s exact test.
 h = fishertest (x) performs Fisher’s exact test on a
  contingency table given in matrix x. This is a test of the
 hypothesis that there are no non-random associations between the two 2-level
 categorical variables in x.  fishertest returns the result of
 the tested hypothsis in h.  h = 0 indicates that the null
 hypothesis (of no association) cannot be rejected at the 5% significance
 level.  h = 1 indicates that the null hypothesis can be rejected at the
 5% level.  x must contain only non-negative integers.  Use the
 crostab function to generate the contingency table from samples of two
 categorical variables.  Fisher’s exact test is not suitable when all integers
 in x are very large.  Use can use the Chi-square test in this case.
 [h, pval] = fishertest (x) returns the p-value in
 pval.  That is the probability of observing the given result, or one
 more extreme, by chance if the null hypothesis is true.  Small values of
 pval cast doubt on the validity of the null hypothesis.
 [p, pval, stats] = fishertest (…) returns the
 structure stats with the following fields:
| OddsRatio | – the odds ratio | |
| ConfidenceInterval | – the asymptotic confidence
 interval for the odds ratio.  If any of the four entries in the contingency
 table x is zero, the confidence interval will not be computed, and [-Inf Inf]will be displayed. | 
 […] = fishertest (…, name, value, …)
 specifies one or more of the following name/value pairs:
| Name | Value | |
|---|---|---|
| "alpha" | the significance level. Default is 0.05. | |
| "tail" | a string specifying the alternative hypothesis | 
| "both" | odds ratio not equal to 1, indicating association between two variables (two-tailed test, default) | |
| "left" | odds ratio greater than 1 (right-tailed test) | |
| "right" | odds ratio is less than 1 (left-tailed test) | 
See also: crosstab, chi2test, mcnemar_test, ztest2
Source Code: fishertest
| 
 ## A Fisher's exact test example
 x = [3, 1; 1, 3]
 [h, p, stats] = fishertest(x)
x =
   3   1
   1   3
h = 0
p = 0.4857
stats =
  scalar structure containing the fields:
    OddsRatio = 9
    ConfidenceInterval =
         0.3666   220.9270
                     |