izi-math

GitHub Repository

Cross-platform deterministic custom implementation of certain math operations:

• sqrt — bisection method
• sin — Taylor series with error bound
• cos — Taylor series with error bound

Motivation

For some projects I need cross-platform determinism more than I need accuracy for these operations. Also felt like applying some basic knowledge I learned in university.

Installation

npm install izi-math

Usage

import { init, sqrt, sin, cos } from 'izi-math';

await init(); // load the wasm module (call once)

// Square root
sqrt(16);           // 4
sqrt(2);            // 1.41421356...
sqrt(2, 0.01);      // 1.41... (looser tolerance, faster)

// Sine (radians)
sin(Math.PI / 2);   // { ans: 1, error: 2.55e-254 }
sin(1, 5);          // { ans: 0.8416..., error: 0.00001... } (fewer iterations)

// Cosine (radians)
cos(0);             // { ans: 1, error: 0 }
cos(Math.PI);       // { ans: -1, error: 2.55e-254 }

Available functions

| Function | Signature | Description | |---|---|---| | sqrt | (a, tolerance?) → number | Square root via bisection (returns NaN if a < 0) | | sin | (x, taylor_iters?) → { ans, error } | Sine via Taylor series (x in radians) | | cos | (x, taylor_iters?) → { ans, error } | Cosine via Taylor series (x in radians) |

Defaults

| Parameter | Default | Notes | |---|---|---| | tolerance | 1e-8 | Minimum allowed value is 1e-8 | | taylor_iters | 170 | Must be an integer in the range [1, 170] |

Contributing

See CONTRIBUTING.md for build instructions, prerequisites, and how to add new functions.