[![Arduino CI](https://github.com/RobTillaart/Fraction/workflows/Arduino%20CI/badge.svg)](https://github.com/marketplace/actions/arduino_ci)
[![Arduino-lint](https://github.com/RobTillaart/Fraction/actions/workflows/arduino-lint.yml/badge.svg)](https://github.com/RobTillaart/Fraction/actions/workflows/arduino-lint.yml)
[![JSON check](https://github.com/RobTillaart/Fraction/actions/workflows/jsoncheck.yml/badge.svg)](https://github.com/RobTillaart/Fraction/actions/workflows/jsoncheck.yml)
[![License: MIT](https://img.shields.io/badge/license-MIT-green.svg)](https://github.com/RobTillaart/Fraction/blob/master/LICENSE)
[![GitHub release](https://img.shields.io/github/release/RobTillaart/Fraction.svg?maxAge=3600)](https://github.com/RobTillaart/Fraction/releases)


# 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

```cpp
#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.

```cpp
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