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
"logical"; 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.