setters {relations} | R Documentation |
Modify relations by (re)setting their domain, graph, or incidences.
relation_domain(x) <- value relation_domain_names(x) <- value relation_graph(x) <- value relation_incidence(x) <- value
x |
an R object inheriting from class relation . |
value |
for setting the domain, a tuple (or list) as long as the
arity of the relation x , with sets of cardinality (for lists:
numbers of elements) identical to the size of x .
For setting the graph, either a set of tuples of equal lengths (arity of the relation) or a data frame or something coercible to this, with the values of the components of the given tuples (rows) always elements of the corresponding elements of the domain of x .
For setting incidences, a numeric array with values in the unit interval or a logical array, with dimension the size of the relation x .
For setting the domain names, a character vector as long as the arity of the relation x .
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relation_domain
for getting the domain of a relation;
relation_domain_names
for getting the domain names;
relation_graph
for getting the graph;
relation_incidence
for getting the incidences;
relation
for basic information.
R <- as.relation(1 : 3) print(R) relation_domain(R) ## tuple format: relation_domain(R) <- pair(X = set("a","b","c"), Y = set("A","B","C")) relation_domain(R) ## the same in list format: relation_domain(R) <- list(X = letters[1:3], Y = LETTERS[1:3]) relation_domain(R) relation_domain_names(R) <- c("XX","YY") relation_domain_names(R) relation_incidence(R) relation_incidence(R) <- diag(1, 3, 3) relation_incidence(R) relation_graph(R) ## set format: relation_graph(R) <- set(pair("a","B"), pair("a","C"), pair("b","C")) relation_graph(R) ## the same in data frame format: relation_graph(R) <- data.frame(c("a", "a", "b"), c("B", "C", "C"), stringsAsFactors = FALSE) relation_graph(R)