rational_number

Introduction

This Fortran module implements several procedures for handling rational numbers. Currently implemented are:

Data types

• rationalnumber_t

Procedures

Name	Type	Description
ratNumInit	function	Initializes a new rationalnumber_t variable with given numerator and denominator values.
ratNumInitFromReal	function	Initializes a new rationalnumber_t variable from a real value.
ratNumToStr	function	Converts a rationalnumber_t variable into its string representation.
ratNumEqualize	subroutine	Makes the denominators of two rationalnumber_t variables equal.
ratNumSimplify	function	Simplifies a rationalnumber_t variable, reducing its numerator and denominator without affecting its value. E.g. 5/10 --> 1/2.
ratNumAdd	function	Adds two rationalnumber_t variables together.
ratNumSubstract	function	Substracts two rationalnumber_t variables.
ratNumSetNumerator	subroutine	Sets the numerator value.
ratNumGetNumerator	function	Returns the numerator value.
ratNumSetDenominator	subroutine	Sets the denominator value. Has no effect if the new value is 0.
ratNumGetDenominator	function	Returns the denominator value.
ratNumToReal	function	Converts a rationalnumber_t variable into its standard Fortran real value representation.

Known bugs/limitations

1. No integer overflow detection/handling. Behaviour is undefined with numerator or denominator values exceeding the limits of the standard Fortran integer type.
2. Currently there are no procedures for other basic operations than addition.

Dependencies

The only dependency is the math module. This module will be included automatically when compiled by FPM.

Building the library:

• Install FPM (Fortran Package Manager) and copy it into your $PATH as fpm.
• Clone the git repository.
• Execute the command fpm build inside the base directory of the repository. This will also fetch and build the required math library.
• This library includes a simple test program. It can be easily executed with fpm test.

This library was compiled with GFortran and packaged with FPM.