Provides the generic functions and the S4 methods is.subset and
is.superset for finding super or subsets in associations and
itemMatrix objects.
Usage
is.subset(x, y = NULL, proper = FALSE)
is.superset(x, y = NULL, proper = FALSE)
Arguments
x, y
associations or itemMatrix objects. If y = NULL,
the super or subset structure within set x is calculated.
proper
a logical indicating if all or just proper super or subsets.
Value
returns a logical matrix with length(x) rows and length(y)
columns. Each logical row vector represents which elements in y are
supersets (subsets) of the corresponding element in x. If either
x or y have lenght zero, NULL is returned instead of a
matrix.
Details
looks for each element in x which elements in y are supersets or
subsets. Note that the method can be very slow and memory intensive if
x and/or y contain many elements.