Maps one coordinate of a contour's grid onto the data axis it stands for.
Not a DataAccessor: the input is a single number from a coordinate pair, not a bound datum, and there is no element index to pass.
Maps one coordinate of a contour's grid onto the data axis it stands for.
Not a DataAccessor: the input is a single number from a coordinate pair, not a bound datum, and there is no element index to pass.