Fraction

Arduino library to implement a Fraction data type (experimental).

Description

The fraction library implements fractional numbers a.k.a. Q, (integers are Z and floats/doubles are R), and the conversion to floats.

The code is working with a number of limitations a.o.:

• denominator is max 4 digits to keep code for multiply and divide simple
• Fractions are not exact, even floats are not exact.
• the range of numbers supported is limited.
• code is experimental still.

That said, the library is useful e.g. to display float numbers as a fraction. From programming point of view the fractionize(float) function, converting a double into a fraction is a nice programming problem, fast with a minimal error.

In short, use fractions with care otherwise your sketch might get broken ;)

Interface

#include "fraction.h"

Constructors

• explicit Fraction(double)
• explicit Fraction(float)
• Fraction(int32_t nominator, int32_t denominator)
• explicit Fraction(int32_t p)
• explicit Fraction(int16_t p)
• explicit Fraction(int8_t p)
• explicit Fraction(uint32_t p)
• explicit Fraction(uint16_t p)
• explicit Fraction(uint8_t p)
• Fraction(const Fraction &f)

Printable

The Fraction library implements the Printable interface, so one can do.

Fraction fr(PI);

Serial.print(fr);  //  print 355/113

Equalities

The Fraction library implements ==, !=, >=, >, <, <=

Basic Math

The Fraction library implements, + - * / += -= *= /= and - (negation)

Conversion

• double toDouble() idem.
• float toFloat() idem.
• bool isProper() absolute value < 1.
• float toAngle() returns 0..360 degrees.
• int32_t nominator() idem.
• int32_t denominator() idem.

Miscellaneous (static)

• Fraction mediant(const Fraction&, const Fraction&)
• Fraction middle(const Fraction&, const Fraction&)
• Fraction setDenominator(const Fraction&, uint16_t)

Use with care

The library is reasonably tested. If problems arise please open an issue.

Future

Must

• improve documentation
• test test test ...

Should

• performance testing
• investigate divide by zero errors
  • NAN in fraction? => 0/0 ?
  • INF in fraction? => 1/0 and -1/0?
• investigate better fractionize()
  • depends on nom/denom size
  • returns the error..

Could

• extend unit tests
• experiment with bigger nominator/denominator using all of 32767 possibilities ?
• add famous constants as Fraction e.g
  • FRAC_PI = 355/113
  • FRAC_E = 3985/1466

Wont

Support

If you appreciate my libraries, you can support the development and maintenance. Improve the quality of the libraries by providing issues and Pull Requests, or donate through PayPal or GitHub sponsors.

Thank you,