rationalpy 0.1.1

NumPy extension enabling arrays of rational numbers (fractions).

RationalPy

rationalpy is a Python library and extension of NumPy designed for creating and manipulating arrays of rational numbers, represented as exact fractions. It enables users to perform arithmetic operations on arrays while maintaining an exact rational representation.

Table of Contents

• RationalPy
  • Table of Contents
  • Installation
  • Documentation
  • Usage
  • Features
  • Examples
  • License

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Installation

To install rationalpy, use pip:

pip install rationalpy

For optional development dependencies (e.g., testing and documentation), install with:

pip install .[test,docs]

Documentation

For complete documentation, visit the documentation website.

Usage

import rationalpy as rp

# Create a 1D RationalArray object
rarr = rp.rational_array([1, 2], [2, 3])
print(rarr)
# Output: [1/2 2/3]

# Create a 2D array
rarr_2d = rp.rational_array([[1, 2], [3, 4]], [[4, 5], [6, 7]])
print(rarr_2d)
# Output: [[1/4 2/5]
#          [1/2 4/7]]

Note that the arrays are automatically simplified upon instantiation. This behavior can be disabled by setting auto_simplify=False.

Features

• Supports exact arithmetic with fractions.
• Provides numpy-style broadcasting for arrays of rational numbers.
• Supports common arithmetic operations (addition, subtraction, multiplication, and division) as well as some numpy array functions (np.sum, np.concatenate, and more).
• Includes methods for fraction simplification RationalArray.simplify() and finding the least common denominator RationalArray.form_common_denominator().
• Customizable __repr__ for displaying rational arrays in a clean, aligned format.

Examples

Simple arithmetic:

import rationalpy as rp

rarr1 = rp.rational_array([0, 1, 2, 3, 4], [1, 2, 3, 4, 5])
print(rarr1)
# Output: [0/1 1/2 2/3 3/4 4/5]

rarr2 = rp.rational_array(1, [1, 2, 3, 4, 5])
print(rarr2)
# Output: [1/1 1/2 1/3 1/4 1/5]

print(rarr1 + rarr2)
# Output: [1/1 1/1 1/1 1/1 1/1]

print(rarr1 - rarr2)
# Output: [-1/1 0/1 1/3 1/2 3/5]

print(rarr1 * rarr2)
# Output: [0/1 1/4 2/9 3/16 4/25]

print(rarr1 / rarr2)
# Output: [0/1 1/1 2/1 3/1 4/1]

Call basic numpy functions:

import numpy as np

for N in range(1, 11):
    rarr = rp.rational_array(1, np.arange(1, N + 1))
    print(f"S_{N}={np.sum(rarr)}")
# Output: S_1=1/1
#         S_2=3/2
#         S_3=11/6
#         S_4=25/12
#         S_5=137/60
#         S_6=49/20
#         S_7=363/140
#         S_8=761/280
#         S_9=7129/2520
#         S_10=7381/2520

Convert back to numpy arrays:

rarr = rp.rational_array([1, 2], [2, 3])
print(rp.asnumpy(rarr))
# Output: [0.5       0.66666667]

License

This project is licensed under the MIT License. See LICENSE for more information.