ExtractTaxa() returns a matrix with n rows, each named for the
relevant taxon, and c columns,
each corresponding to the respective character specified in character_num.
NexusTokens() returns a character vector in which each entry
corresponds to the states of a phylogenetic character, or a list containing
an error message if input is invalid.
Arguments
matrixLines
Character vector containing lines of a file that include
a phylogenetic matrix. See ReadCharacters() for expected format.
character_num
Index of character(s) to return.
NULL, the default, returns all characters.
continuous
Logical specifying whether characters are continuous.
Treated as discrete if FALSE.
tokens
Vector of character strings corresponding to phylogenetic
tokens.