Functions to validate permutations

Functions to validate permutation objects: if valid, return TRUE and if not valid, generate a warning() and return FALSE.

Function singleword_valid() takes an integer vector, interpreted as a word, and checks that it is a permutation of seq_len(max(x)).

Function cyclist_valid() takes a cyclist and checks that its argument corresponds to a meaningful permutation: the elements must be vectors of strictly positive integers with no repeated values and empty pairwise intersection. Compare nicify_cyclist() [documented at cyclist.Rd] which is more cosmetic, converting its argument into a standard form.

Usage

singleword_valid(w)
cyclist_valid(x)

Arguments

w

In function singleword_valid(), an integer vector

x

In function cyclist_valid(), a cyclist

Value

Returns either TRUE, or gives a warning and returns FALSE

Author

Robin K. S. Hankin

See also

cyclist

Examples

singleword_valid(sample(1:9))      # TRUE
#> [1] TRUE
singleword_valid(c(3L,4L,2L,1L))   # TRUE
#> [1] TRUE
singleword_valid(c(3,4,2,1))       # FALSE (not integer)
#> Warning: invalid word
#> [1] FALSE
singleword_valid(c(3L,3L,2L,1L))   # FALSE (3 repeated)
#> Warning: invalid word
#> [1] FALSE

cyclist_valid(list(c(1,8,2),c(3,6))) # TRUE
#> [1] TRUE
cyclist_valid(list(c(1,8,2),c(3,6))) # FALSE ('8' is repeated)
#> [1] TRUE
cyclist_valid(list(c(1,8,1),c(3,6))) # FALSE ('1' is repeated)
#> Warning: repeated value
#> [1] FALSE
cyclist_valid(list(c(0,8,2),c(3,6))) # FALSE (zero element)
#> Warning: zero element
#> [1] FALSE