The uncertainty coefficient U(C|R) measures the proportion of uncertainty (entropy) in the column variable Y that is explained by the row variable X. The function has interfaces for a table, a matrix, a data.frame and for single vectors.
UncertCoef(x, y = NULL, direction = c("symmetric", "row", "column"),
conf.level = NA, p.zero.correction = 1/sum(x)^2, ...)
Either a single numeric value, if no confidence interval is required,
or a vector with 3 elements for estimate, lower and upper confidence intervall.
a numeric vector, a factor, matrix or data frame.
NULL
(default) or a vector, an ordered factor, matrix or data frame with compatible dimensions to x.
direction of the calculation. Can be "row"
(default) or "column"
, where
"row"
calculates UncertCoef (R|C) ("column dependent").
confidence level of the interval. If set to NA
(which is the default) no confidence interval will be calculated.
slightly nudge zero values so that their logarithm can be calculated
further arguments are passed to the function table
, allowing i.e. to set useNA. This refers only to the vector interface.
Andri Signorell <andri@signorell.net> strongly based on code from Antti Arppe <antti.arppe@helsinki.fi>
The uncertainty coefficient is computed as
Theil, H. (1972), Statistical Decomposition Analysis, Amsterdam: North-Holland Publishing Company.
Entropy
, Lambda
, Assocs
# example from Goodman Kruskal (1954)
m <- as.table(cbind(c(1768,946,115), c(807,1387,438), c(189,746,288), c(47,53,16)))
dimnames(m) <- list(paste("A", 1:3), paste("B", 1:4))
m
# direction default is "symmetric"
UncertCoef(m)
UncertCoef(m, conf.level=0.95)
UncertCoef(m, direction="row")
UncertCoef(m, direction="column")
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