PyExpressions Library

by Alvin Wan and Nathan Pucheril

Getting Started

To use, install via PyPi.

pip install PyExpressions

To use, import needed scripts and see below for the appropriate section.

import pyexpressions

# or
from pyexpressions import Polynomial

Discrete Mathametics

This library supports the following methods.

• Lagrange Interpolation: PyExpressions.lagrangeinterpolation.interpolate
• Lagrange Interpolation in a Galois Field: TODO

Polynomial

The polynomial (will eventually be) is designed to be type-agnostic. Coefficients can be any numerical type, even custom-made.

Polynomials accept human-readable input and evaluate to human-readable output.

>>> Polynomial('3x^6 + 2x^2 + x + 1')
3x^6 + 2x^2 + x + 1

In addition, this Polynomial class supports standard mathematical operations, that can be mixed with other numerical types.

>>> p, q, r = P('1'), P('2x + 3'), ('3x^4 + 2x^2 + 1')
>>> p + q
2x + 4
>>> r * 4
12x^4 + 8x^2 + 4

The polynomial can then be evaluated at various points, as you would expect a Polynomial to do.

>>> x2 = P('x^2')
>>> x2(-1)
1
>>> x2(3)
9