Returns expected counts before comparing response probabilities (i.e. when the response variable is a binary variable) to given values by a chi-squared test. The function is in fact a wrapper to the chi-squared test for comparison of proportions to given values on a contingency table.
chisq.bin.exp(formula, data, p, graph = FALSE)
theoretical probabilities.
contingency table of expected counts.
number of counts which can be < 5.
a formula of the form a ~ b, where a and b give the data values and corresponding groups, respectively. a can be a numeric vector or a factor, with only two possible values (except NA).
an optional data frame containing the variables in the formula formula. By default the variables are taken from environment(formula).
theoretical probabilities.
logical. If TRUE a mosaic plot of expected counts is drawn.
Maxime HERVE <maxime.herve@univ-rennes1.fr>
The function returns how many counts can be < 5 to respect Cochran's rule (80% of counts must be >= 5).
prop.test, chisq.theo.bintest, mosaicplot
response <- c(rep(0:1,c(40,60)),rep(0:1,c(55,45)),rep(0:1,c(65,35)))
fact <- gl(3,100,labels=LETTERS[1:3])
p.theo <- c(0.5,0.45,0.2)
chisq.bin.exp(response~fact,p=p.theo)
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