Mathematical Constants & Types

/** Mathematical constant π (pi) */
const PI: number;

/** Mathematical constant τ (tau) = 2π */
const TAU: number;

/** Half of π */
const HALF_PI: number;

/** Third of π */
const THIRD_PI: number;

/** Quarter of π */
const QUARTER_PI: number;

/** Sixth of π */
const SIXTH_PI: number;

/** Inverse of π (1/π) */
const INV_PI: number;

/** Inverse of τ (1/τ) */
const INV_TAU: number;

/** Inverse of π/2 (2/π) */
const INV_HALF_PI: number;

/** Degrees to radians conversion factor (π/180) */
const DEG2RAD: number;

/** Radians to degrees conversion factor (180/π) */
const RAD2DEG: number;

/** Golden ratio φ = (1 + √5) / 2 */
const PHI: number;

/** Square root of 2 */
const SQRT2: number;

/** Square root of 3 */
const SQRT3: number;

/** Square root of 2 divided by 2 */
const SQRT2_2: number;

/** Square root of 3 divided by 2 */
const SQRT3_2: number;

/** One third (1/3) */
const THIRD: number;

/** Two thirds (2/3) */
const TWO_THIRD: number;

/** One sixth (1/6) */
const SIXTH: number;

/** Default epsilon value for floating-point comparisons */
let EPS: number;

import { PI, TAU, PHI, DEG2RAD, EPS } from "@thi.ng/math/api";

// Circle calculations
const circumference = TAU * radius;
const area = PI * radius ** 2;

// Golden ratio applications
const goldenRectangleRatio = PHI; // 1.618...

// Angle conversions
const radians = 45 * DEG2RAD; // π/4

// Floating-point comparisons
const isZero = Math.abs(value) < EPS;

/**
 * Classification of line crossing relationships
 */
type Crossing = 
  /** Lines A & B are equal */
  | "equal"
  /** Lines A & B are flat (all same values) */
  | "flat"
  /** Line A crossed under B */
  | "under"
  /** Line A crossed over B */
  | "over"
  /** Other crossing relationship */
  | "other";

/**
 * Numeric array type (imported from @thi.ng/api)
 * Union of typed array types for numerical computations
 */
type NumericArray = 
  | number[]
  | Float32Array 
  | Float64Array
  | Int8Array
  | Int16Array
  | Int32Array
  | Uint8Array
  | Uint16Array
  | Uint32Array
  | Uint8ClampedArray;

import { classifyCrossing, type Crossing } from "@thi.ng/math/crossing";
import { type NumericArray } from "@thi.ng/math/api";

// Crossing type usage
const classification: Crossing = classifyCrossing(1, 3, 2, 4);
// Returns "over" since line A crosses over line B

// NumericArray type usage  
const processArray = (data: NumericArray): number => {
  // Function can accept any numeric array type
  return data.reduce((sum, val) => sum + val, 0);
};

processArray([1, 2, 3]); // Works with regular arrays
processArray(new Float32Array([1.5, 2.5, 3.5])); // Works with typed arrays