This enumeration provides the special values for use as the index when retrieving choice values through the functions IG_ISIS_choice_get_long, IG_ISIS_choice_get_rational. They are not valid for IG_ISIS_choice_get_ascii.

Values:

IG_ISIS_CHOICE_LOW	Value indicating to retrieve the lowest value in a range, or the first value in a list.
IG_ISIS_CHOICE_HIGH	Value indicating to retrieve the highest value in a range, or the last value in a list.
IG_ISIS_CHOICE_STEP	Value indicating to retrieve the step value in a range.