is_graph6 function

Infer or test for graph6, sparse6, and digraph6 symbols

Functions is_graph6(), is_sparse6()), and is_digraph6() test if elements of a character vector are valid symbols of particular type.

Function guess_format() tries to guess the type of the symbols used in x.

is_graph6(x)

is_sparse6(x)

is_digraph6(x)

guess_format(x)

Arguments

• x: character vector

Returns

Logical vector of length equal to length(x) with TRUE if an element is a valid symbol and FALSE otherwise.

Function guess_format() returns a character vector of the same length as x with values "graph6", "sparse6", or "digraph6" depending on the type of symbol present, or NA if the symbol is unknown or matches more than one type.

Note

At this moment the test is performed using regular expressions. Theoretically it may result in false positives.

Examples

all(is_graph6(g6))
all(is_sparse6(s6))
all(is_digraph6(d6))

# Vector mixing graphs in various formats
x <- g6
x[seq(2, 20, by = 3)] <- s6[seq(2, 20, by = 3)]
x[seq(3, 20, by = 3)] <- d6[seq(3, 20, by = 3)]
guess_format(x)