math-problems

Solve math problems easily with this utility library. Includes temperature conversions, geometric area calculations, number utilities, and population statistics.

Installation

npm install math-problems

Usage

import {
  area,
  toCelsius,
  isEven,
  populationDensity,
  population,
} from 'math-problems';

// Calculate the area of a circle with radius 5
console.log(area.circle(5)); // 78

// Convert 73°F to Celsius
console.log(toCelsius(73)); // 22.777... (repeating decimal)

// Check if a number is even
console.log(isEven(4)); // true

// Calculate population density
console.log(populationDensity(11452000, 1483)); // 7724

// Access population data
console.log(population.br.sp); // 11452000

API Documentation

📐 Area Calculations

All area functions return an object with a floored area value.

• Rectangle
  rect(base: number, height: number)
area.rect(4, 5) ➔ 20

• Triangle
  triangle(base: number, height: number)
area.triangle(4, 5) ➔ 10

• Rhombus
  rhombus(D: number, d: number)
area.rhombus(8, 6) ➔ 24

• Trapezoid
  trapezoid(B: number, b: number, height: number)
area.trapezoid(10, 6, 5) ➔ 40

• Circle
  circle(radius: number)
area.circle(3) ➔ 28

🌡️ Temperature Conversions

Convert between Celsius (°C), Fahrenheit (°F), and Kelvin (K).

• toCelsius
  toCelsius(temperature: number, unit?: 'F' | 'K')
  Default unit: Fahrenheit
  toCelsius(32) ➔ 0
toCelsius(273.15, 'K') ➔ 0

• toFahrenheit
  toFahrenheit(temperature: number, unit?: 'C' | 'K')
  Default unit: Celsius
  toFahrenheit(0) ➔ 32
toFahrenheit(273.15, 'K') ➔ 32

• toKelvin
  toKelvin(temperature: number, unit?: 'C' | 'F')
  Default unit: Celsius
  toKelvin(0) ➔ 273
toKelvin(32, 'F') ➔ 273

🔢 Number Utilities

• isEven(number)
  Returns true if the number is even.

• isOdd(number)
  Returns true if the number is odd.

• difference(x, y)
  Returns the floored difference between two numbers.
  difference(10, 3.8) ➔ 6

• PI
  Math.PI constant (≈3.14159).

📊 Interpoolation and regression

• interpolation(input: { function: (number) => number, value: number, points: number[] })
  Interpolates a set of data points from a function and value through Newton Interpolation.

interpolation({
  function: Math.log,
  value: 2,
  points: [1, 4, 6]
})

➔ 0.5658443469009827

• regression(input: number[])
  Computes the linear and polynomial regression from a set of data points.

regression([
  [-2, -1],
  [1, 2],
  [4, 59],
  [-1, 4],
  [3, 24],
  [-4, -53]
]);

➔ {
  linear: {
    m: 10.97864768683274,
    b: 4.00355871886121
  },
  polynomial: {
    a: 6.689189189189188,
    b: 11.060810810810809,
    c: -0.34459459459459435
  }
}

📊 Population Statistics

• populationDensity(population, area)
  Returns density (people per unit area).

• birthRate(births, population)
  Returns births per 1000 people.

• deathRate(deaths, population)
  Returns deaths per 1000 people.

• Population Data
  Pre-defined population figures (as of Feb 2025):

  population.br.sp; // Brazil São Paulo: 11,452,000
  population.us.ny; // USA New York: 20,201,249

Contributing

Contributions are welcome! Please follow the contribution guidelines.

1. Clone the repository:

   git clone https://github.com/igorwastaken/math-utils.git

2. Install dependencies:

   npm install

3. Run tests:

   npm test

License

MIT © Igor Figueiredo
Full License Text