@wollybeard/kit

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Num.Frac ​

Num / Frac

Import ​

typescript
import { Num } from '@wollybeard/kit'

// Access via namespace
Num.Frac.someFunction()
typescript
import * as Num from '@wollybeard/kit/num'

// Access via namespace
Num.Frac.someFunction()

Functions ​

[F] is ​

typescript
(value: unknown): boolean
Source

Parameters:

  • value - The value to check

Returns: True if value is a proper fraction (0 n/d 1)

Type predicate to check if value is a proper fraction.

[F] from ​

typescript
(numerator: Natural, denominator: Natural): Frac
Source

Parameters:

  • numerator - The top number (positive, less than denominator)
  • denominator - The bottom number (positive, greater than numerator)

Returns: The fraction

Throws:

  • Error if not a proper fraction

Construct a Fraction from numerator and denominator. Both must be positive and numerator must be less than denominator.

[F] tryFrom ​

typescript
(numerator: Natural, denominator: Natural): Frac | null
Source

Parameters:

  • numerator - The top number
  • denominator - The bottom number

Returns: The fraction or null

Try to construct a Fraction. Returns null if not a proper fraction.

[F] fromDecimal ​

typescript
(value: number, maxDenominator?: number = 100): Frac
Source

Parameters:

  • value - The decimal value (0 value 1)
  • maxDenominator - Maximum denominator to use (default: 100)

Returns: The fraction approximation

Throws:

  • Error if value is not between 0 and 1

Convert a decimal to a fraction. The decimal must be between 0 and 1 (exclusive).

[F] toDecimal ​

typescript
(frac: Frac): number
Source

Parameters:

  • frac - The fraction to convert

Returns: The decimal value (between 0 and 1)

Convert fraction to decimal.

[F] toPercentage ​

typescript
(frac: Frac): number
Source

Parameters:

  • frac - The fraction to convert

Returns: The percentage value (0-100)

Convert fraction to percentage.

[F] complement ​

typescript
(frac: Frac): Frac
Source

Parameters:

  • frac - The fraction

Returns: The complement as a fraction

Get the complement of a fraction (1

  • fraction).

[F] add ​

typescript
(a: Frac, b: Frac): Ratio
Source

Parameters:

  • a - First fraction
  • b - Second fraction

Returns: The sum as a Ratio (might be = 1)

Add two fractions. Note: The result might not be a fraction if the sum = 1.

[F] multiply ​

typescript
(a: Frac, b: Frac): Frac
Source

Parameters:

  • a - First fraction
  • b - Second fraction

Returns: The product as a fraction

Multiply two fractions. The result is always a fraction (product of two numbers

1 is

1).

[F] compare ​

typescript
(a: Frac, b: Frac): 0 | 1 | -1
Source

Parameters:

  • a - First fraction
  • b - Second fraction

Returns: -1 if a b, 0 if a = b, 1 if a b

Compare two fractions.

Constants ​

[C] fromWith ​

typescript
;((numerator: Natural) => (denominator: Natural) => Frac)
Source

Create a function that constructs fractions with a fixed numerator. Useful for creating series of fractions.

[C] fromOn ​

typescript
;((denominator: Natural) => (numerator: Natural) => Frac)
Source

Create a function that constructs fractions with a fixed denominator. Useful for working with common denominators.

[C] addOn ​

typescript
;((a: Frac) => (b: Frac) => Ratio)
Source

Create a function that adds to a specific fraction. Data-first pattern: fix the first argument.

[C] addWith ​

typescript
;((b: Frac) => (a: Frac) => Ratio)
Source

Create a function that adds with a specific fraction. Data-second pattern: fix the second argument.

[C] multiplyOn ​

typescript
;((a: Frac) => (b: Frac) => Frac)
Source

Create a function that multiplies a specific fraction. Data-first pattern: fix the first argument.

[C] multiplyWith ​

typescript
;((b: Frac) => (a: Frac) => Frac)
Source

Create a function that multiplies with a specific fraction. Data-second pattern: fix the second argument.

[C] compareOn ​

typescript
;((a: Frac) => (b: Frac) => 0 | 1 | -1)
Source

Create a function that compares a specific fraction. Data-first pattern: fix the first argument.

[C] compareWith ​

typescript
;((b: Frac) => (a: Frac) => 0 | 1 | -1)
Source

Create a function that compares with a specific fraction. Data-second pattern: fix the second argument.

Types ​

[∩] Frac ​

typescript
type Frac = Ratio & { [FracBrand]: true }
Source

Fraction (proper fraction)

  • a positive ratio where 0

numerator

denominator.

Fractions represent parts of a whole, always between 0 and 1 (exclusive). They're ideal for:

  • Probabilities (1/6 for dice roll)
  • Portions and percentages (3/4 of a pizza)
  • UI measurements (2/3 width)
  • Musical note durations (1/4 note, 1/8 note)