fraction 2.0.0-nullsafety.0

A package that helps you dealing with mathematical fractions. Work with fractions, mixed fractions and types conversions.

A package that helps you dealing with fractions and mixed fractions.

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Working with fractions

You can create an instance of Fraction using one of its constructors.

• Basic: it just requires the numerator and/or the denominator.

  final frac = Fraction(3, 5); // 3/5
  final frac = Fraction(3, 1); // 3
  

• String: pass the fraction as a string but it has to be well-formed otherwise an exception is thrown.

  final frac1 = Fraction.fromString("2/4"); // 2/4
  final frac2 = Fraction.fromString("-2/4"); // -2/4
  final frac3 = Fraction.fromString("2/-4"); // Error
  final frac4 = Fraction.fromString("-2"); // -2/1
  

• double: represents a double as a fraction. Note that irrational numbers cannot be converted into a fraction by definition; the constructor has the precision parameter which decides how precise the representation has to be.

  final frac1 = Fraction.fromDouble(1.5); // 3/2
  final frac2 = Fraction.fromDouble(-8.5); // -17/2
  final frac3 = Fraction.fromDouble(math.pi); // 208341/66317
  final frac4 = Fraction.fromDouble(math.pi, 1.0E-4); // 333/106
  

  The constant pi cannot be represented as a fraction because it's an irrational number. The constructor considers only precison decimal digits to create a fraction. With rational numbers instead you don't have problems.

Thanks to extension methods you can also create a Fraction object "on the fly" by calling the toFraction() method on a number or a string.

final f1 = 5.toFraction(); // 5/1
final f2 = 1.5.toFraction(); // 3/2
final f3 = "6/5".toFraction(); // 6/5

Note that a Fraction object is immutable so methods that require changing the internal state of the object return a new instance. For example, reduce() method reduces the fraction to the lowest terms but it returns a new instance:

final fraction = Fraction.fromString("12/20"); // 12/20
final reduced = fraction.reduce(); // now it's simplified to  3/5

Two fractions are equal if their "cross product" is equal. For example 1/2 and 3/6 are said to be equivalent because 1*6 = 3*2 (and in fact 3/6 is the same as 1/2). Be sure to check out the official documentation at pub.dev for a complete overview of the API.

Working with mixed fractions

A mixed fraction is made up of a whole part and a proper fraction (a fraction in which numerator <= denominator). Building MixedFraction objects can't be easier:

final mixed1 = MixedFraction(
  whole: 3, 
  numerator: 4, 
  denominator: 7
);
final mixed2 = MixedFraction.fromDouble(1.5);
final mixed3 = MixedFraction.fromString("1 1/2");

There is also the possibility to initialize a MixedFraction using extension methods, as it happens with Fraction:

final mixed = "1 1/2".toMixedFraction();

Note that MixedFraction objects are immutable exactly like Fraction objects so you're guaranteed that the internal state of the instance won't change during its lifetime.