The identity permutation leaves every element fixed
is.id(x)
is.id_single_cycle(x)
# S3 method for cycle
is.id(x)
# S3 method for list
is.id(x)
# S3 method for word
is.id(x)
Object to be tested
The variable id
is a cycle as this is more convenient
than a zero-by-one matrix.
Function is.id()
returns a Boolean with TRUE
if the
corresponding element is the identity, and FALSE
otherwise. It
dispatches to either is.id.cycle()
or is.id.word()
as
appropriate.
Function is.id.list()
tests a cyclist for identityness.
The identity permutation is problematic because it potentially has zero size.
# NOT RUN { is.id(id) as.word(id) # weird x <- rperm(10,4) x[3] <- id is.id(x*inverse(x)) # }