Value Matching
Provides the generic function match and the S4 methods for
associations, transactions and itemMatrices. match returns a vector
of the positions of (first) matches of its first argument in its second.
%in% is a more intuitive interface as a binary operator, which
returns a logical vector indicating if there is a match or not for
the items in the itemsets (left operand) with the items in the table
(right operand).
arules defines additional binary operators for matching itemsets:
%pin% uses partial matching on the table;
%ain% itemsets have to match/include all items in the table;
%oin% itemsets can only match/include the items in the table.
The binary matching operators or often used in subset.
match(x, table, nomatch = NA_integer_, incomparables = NULL) x %in% table x %pin% table x %ain% table x %oin% table
x |
an object of class |
table |
a set of associations or transactions to be matched against. |
nomatch |
the value to be returned in the case when no match is found. |
incomparables |
not implemented. |
match: An integer vector of the same length as x giving the
position in table of the first match if there is a match, otherwise
nomatch.
%in%, %pin%, %ain%, %oin%:
A logical vector, indicating if a match was located for each
element of x.
Michael Hahsler
data("Adult")
## get unique transactions, count frequency of unique transactions
## and plot frequency of unique transactions
vals <- unique(Adult)
cnts <- tabulate(match(Adult, vals))
plot(sort(cnts, decreasing=TRUE))
## find all transactions which are equal to transaction 10 in Adult
which(Adult %in% Adult[10])
## for transactions we can also match directly with itemLabels.
## Find in the first 10 transactions the ones which
## contain age=Middle-aged (see help page for class itemMatrix)
Adult[1:10] %in% "age=Middle-aged"
## find all transactions which contain items that partially match "age=" (all here).
Adult[1:10] %pin% "age="
## find all transactions that only include the item "age=Middle-aged" (none here).
Adult[1:10] %oin% "age=Middle-aged"
## find al transaction which contain both items "age=Middle-aged" and "sex=Male"
Adult[1:10] %ain% c("age=Middle-aged", "sex=Male")Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.