GY-63_MS5611/libraries/Fraction

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 Printable, 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