3.8 KiB
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
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Thank you,