Calculate coverage for rules
Provides the generic function and the needed S4 method to calculate the coverage (support of the left-hand-side) of rules.
coverage(x, transactions = NULL, reuse = TRUE)
x |
the set of rules. |
transactions |
the data set used to generate 'x'. Only needed if the quality slot of 'x' does not contain support and confidence. |
reuse |
reuse support and confidence stored in 'x' or recompute from transactions? |
Coverage (also called cover or LHS-support) is the support of the left-hand-side of the rule, i.e., supp(X). It represents a measure of to how often the rule can be applied.
Coverage is quickly calculated from the rules quality measures
(support and confidence) stored in the quality slot. If these
values are not present, then the support of the LHS is counted using
the data supplied in transactions.
Coverage is also one of the measures available via the function
interestMeasures.
A numeric vector of the same length as x containing
the coverage values for the sets in x.
Michael Hahsler
data("Income")
## find and some rules (we only use 5 rules here) and calculate coverage
rules <- apriori(Income)[1:5]
quality(rules) <- cbind(quality(rules), coverage = coverage(rules))
inspect(rules)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.