@bedard/math

@bedard/math

This library exists to help me avoid duplicate code between projects. My goal is to expose small, well tested, and tree-shakeable utility functions. Given the simplicity of these, I do not anticipate breaking changes. But be warned, this project is not following semantic versioning.

Installation

The recommended installation method is via NPM.

npm install @bedard/math

Alternatively, these functions maybe be accessed via a CDN. When using a CDN, the library will be exposed globally as BedardMath.

<script src="https://unpkg.com/@bedard/math"></script>

Functions

• angleFrom
• bilerp
• cols
• degreesToRadians
• flattenCols
• flattenRows
• flip
• intersect
• isEven
• lerp
• measure
• polygon
• radiansToDegrees
• rotateMatrix
• rotateVector
• rows
• slope

angleFrom

Calculate angled distance from a vector. An angle of 0 degrees will track along the X axis, with positive angles rotating counter-clockwise.

import { angleFrom } from '@bedard/math'

angleFrom([0, 0], 90, 1) // [0, 1] (approximate)

bilerp

Bi-linear interpolation between vectors.

import { bilerp } from '@bedard/math'

bilerp([0, 0], [10, 10], 0.5) // [5, 5]

cols

Chunk a square matrix into columns. Note that the source matrix must be provided in row-major order.

import { cols } from '@bedard/math'

cols([
  0, 1, 2,
  3, 4, 5,
  6, 7, 8,
]) // [[0, 3, 6], [1, 4, 7], [2, 5, 8]]

degreesToRadians

Convert degrees to radians.

import { degreesToRadians } from '@bedard/math'

degreesToRadians(180) // 3.141592653589793

flattenCols

Flatten an array of columns to a matrix in row-major order.

import { flattenCols } from '@bedard/math'

flattenCols([
  [0, 3, 6],
  [1, 4, 7],
  [2, 5, 8],
]) // [0, 1, 2, 3, 4, 5, 6, 7, 8]

flattenRows

Flatten an array of rows to a matrix in row-major order.

import { flattenRows } from '@bedard/math'

flattenRows([
  [0, 1, 2],
  [3, 4, 5],
  [6, 7, 8],
]) // [0, 1, 2, 3, 4, 5, 6, 7, 8]

flip

Convert between rows and columns. A good way to visualize this operation is holding a card by the top-left and bottom-right corners and flipping it over.

import { flip } from '@bedard/math'

flip([
  [0, 1, 2],
  [3, 4, 5],
  [6, 7, 8],
]) // [[0, 3, 6], [1, 4, 7], [2, 5, 8]]

intersect

Intersect two-dimensional lines. Returns undefined if lines are parellel.

import { intersect } from '@bedard/math'

intersect([[-1, 0], [1, 0]], [[0, 1], [0, -1]]) // [0, 0]

isEven

Test if a number is even.

import { isEven } from '@bedard/math'

isEven(2) // true

lerp

Linear interpolation between numbers.

import { lerp } from '@bedard/math'

lerp(0, 10, 0.5) // 5

measure

Measure the distance between two vectors.

import { measure } from '@bedard/math'

// arguments can be provided as a pair of vectors
measure([0, 0], [3, 4]) // 5

// or as a single line argument
measure([[0, 0], [3, 4]]) // 5

polygon

Create a regular polygon. The first argument defines the number of points, with the second defining the circumradius. Points start from the 12 o'clock position, and rotate counter-clockwise around the origin.

import { polygon } from '@bedard/math'

polygon(4, 1) // [[0, 1], [-1, 0], [0, -1], [1, 0]] (approximate)

radiansToDegrees

Convert radians to degrees.

import { radiansToDegrees } from '@bedard/math'

radiansToDegrees(Math.PI) // 180

rotateMatrix

Rotate a square matrix. Positive values apply clockwise rotations.

import { rotateMatrix } from '@bedard/math'

rotateMatrix([
  0, 1, 2,
  3, 4, 5,
  6, 7, 8,
], 1) // [6, 3, 0, 7, 4, 1, 8, 5, 2]

rotateVector

Rotate a vector counter-clockwise around the origin.

import { rotateVector } from '@bedard/math'

rotateVector([0, 1], 90) // [-1, 0] (approximate)

rows

Chunk a square matrix into rows. Note that the source matrix must be provided in row-major order.

import { rows } from '@bedard/math'

rows([
  0, 1, 2,
  3, 4, 5,
  6, 7, 8,
]) // [[0, 1, 2], [3, 4, 5], [6, 7, 8]]

slope

Calculate the slope of a line.

import { slope } from '@bedard/math'

// arguments can be provided as a pair of vectors
slope([0, 0], [1, 1]) // 1

// or as a single line argument
slope([[0, 0], [1, 1]]) // 1

License

MIT

Copyright (c) 2021-present, Scott Bedard