level() can handle length(level) > 1 just fine, until one or more of the levels is not in fct, at which point the error message assumes the level is actually of length 1 when forming the error message, and the if clause will throw an error due to multiple logicals.
Fix the error message and if() to handle the length(level) > 1 case.
level()can handlelength(level) > 1just fine, until one or more of the levels is not infct, at which point the error message assumes thelevelis actually of length 1 when forming the error message, and theifclause will throw an error due to multiple logicals.Fix the error message and
if()to handle thelength(level) > 1case.