fisher.multcomp: Pairwise comparisons using Fisher's exact test

Description Usage Arguments Details Value Author(s) See Also Examples

View source: R/fisher.multcomp.R

Description

Performs pairwise comparisons after a comparison of proportions or after a test for independence of 2 categorical variables, by using a Fisher's exact test.

Usage

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fisher.multcomp(tab.cont, p.method = "fdr")

Arguments

tab.cont

contingency table.

p.method

method for p-values correction. See help of p.adjust.

Details

Since chi-squared and G tests are approximate tests, exact tests are preferable when the number of individuals is small (200 is a reasonable minimum).

Value

method

name of the test.

data.name

a character string giving the name(s) of the data.

p.adjust.method

method for p-values correction.

p.value

table of results of pairwise comparisons.

Author(s)

Maxime Herv<e9> <[email protected]>

See Also

chisq.test, prop.test, fisher.test

Examples

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# 2-column contingency table: comparison of proportions
tab.cont1 <- matrix(c(17,23,12,24,20,10),ncol=2,dimnames=list(c("Control",
  "Treatment1","Treatment2"),c("Alive","Dead")),byrow=TRUE)
fisher.test(tab.cont1)
fisher.multcomp(tab.cont1)

# 3-column contingency table: independence test
tab.cont2 <- as.table(matrix(c(25,10,12,6,15,14,9,16,9),ncol=3,dimnames=list(c("fair",
  "dark","russet"),c("blue","brown","green"))))
fisher.test(tab.cont2)
fisher.multcomp(tab.cont2)

Example output

*** Package RVAideMemoire v 0.9-68 ***

	Fisher's Exact Test for Count Data

data:  tab.cont1
p-value = 0.02316
alternative hypothesis: two.sided


        Pairwise comparisons using Fisher's exact test for count data

data:  tab.cont1

           Control Treatment1
Treatment1 0.48195          -
Treatment2 0.08352    0.03839

P value adjustment method: fdr

	Fisher's Exact Test for Count Data

data:  tab.cont2
p-value = 0.005733
alternative hypothesis: two.sided


        Pairwise comparisons using Fisher's exact test for count data

data:  tab.cont2

            blue:brown blue:green brown:green
fair:dark      0.02211    0.03435      0.7793
fair:russet    0.03435    0.44655      0.4801
dark:russet    0.77935    0.44655      0.5362

P value adjustment method: fdr

RVAideMemoire documentation built on Aug. 21, 2017, 5:07 p.m.