View:	Hide Browser | Browser on the left | Browser on the right | Dictionary
Report:	General Info | Attributes | Operations | Constraints

---

Parent Package: quantity
Class DV_PROPORTION

DV_AMOUNT, PROPORTION_KIND
   |
   +--DV_PROPORTION
Models a ratio of values, i.e. where the numerator and denominator are both pure numbers.

Attributes
Signature	Optionality	Multiplicity	Constant	Documentation
denominator : Real	1	--		denominator of ratio
numerator : Real	1	--		numerator of ratio
precision : Integer	0..1	--		Precision to which the numerator and denominator values of the proportion are expressed, in terms of number of decimal places. The value 0 implies an integral quantity. The value -1 implies no limit, i.e. any number of decimal places.
type : Integer	1	--		Indicates semantic type of proportion, including percent, unitary. Codes are given in PROPORTION_KIND class.

Operations
Signature	Constraints	Documentation
is_strictly_comparable_to(other : DV_PROPORTION) : Boolean	post: other.type implies result	True if type is the same.
magnitude() : Real	post: Result = numerator/denominator	Effective magnitude represented by ratio.

Constraints
Name	Expression
Is_integral_validity	inv: is_integral implies (numerator.floor = numerator and denominator.floor = denominator)
Type_validity	inv: valid_proportion_kind(type)
Fraction_validity	inv: (type = pk_fraction or type = pk_integer_fraction) implies is_integral
Unitary_validity	inv: type = pk_unitary implies denominator = 1
Percent_validity	inv: type = pk_percent implies denominator = 100
Precision_validity	inv: precision = 0 implies is_integral