from,to: Character vector of players to substitute and their substitutes
Details
Function psubs() substitutes one or more player names, replacing player from[i] with to[i]. If argument to is missing, all players are substituted, the second argument taken to be the replacement: interpret psubs(H,vec) as psubs(H,from=pnames(H),to=vec).
Compare pnames<-(), which can only add players, or reorder existing players.
Function psubs_single() is a low-level helper function that takes a single player and its substitute; it is not intended for direct use.