Introduction to Mathjs

Mathjs is a powerful and flexible math library for JavaScript and Node.js. It provides a comprehensive set of tools for working with numbers, big numbers, complex numbers, fractions, units, matrices, and more. It also offers a flexible expression parser, supporting various mathematical functions and constants.

Basic Usage

  
    const { add, subtract, multiply, divide } = require('mathjs');

    console.log(add(2, 3)); // 5
    console.log(subtract(7, 2)); // 5
    console.log(multiply(3, 4)); // 12
    console.log(divide(10, 2)); // 5
  

Working with Complex Numbers

  
    const { complex, add, multiply } = require('mathjs');

    const a = complex(2, 3);
    const b = complex(4, 1);

    console.log(add(a, b)); // Complex { re: 6, im: 4 }
    console.log(multiply(a, b)); // Complex { re: 5, im: 14 }
  

Using Matrices

  
    const { matrix, multiply } = require('mathjs');

    const a = matrix([
      [1, 2],
      [3, 4]
    ]);

    const b = matrix([
      [5, 6],
      [7, 8]
    ]);

    console.log(multiply(a, b));
    // Matrix {
    //   _data: [
    //     [ 19, 22 ],
    //     [ 43, 50 ]
    //   ],
    //   _size: [ 2, 2 ],
    //   _datatype: undefined
    // }
  

Calculating with Units

  
    const { unit, add } = require('mathjs');

    const a = unit('45 cm');
    const b = unit('1 foot');

    console.log(add(a, b).toString()); // '75.48 cm'
  

Polynomial Roots

  
    const { polyRoots } = require('mathjs');

    console.log(polyRoots([1, -3, 2])); // [2, 1]
  

Using the Expression Parser

  
    const { evaluate } = require('mathjs');

    console.log(evaluate('2 + 3 * (4 - 1)')); // 11
  

Sample Application

Here’s an example of a simple calculator app that showcases the power of Mathjs APIs.

  
    const { evaluate } = require('mathjs');
    const readline = require('readline').createInterface({
      input: process.stdin,
      output: process.stdout
    });

    console.log("Welcome to Mathjs Calculator");
    readline.setPrompt('Enter expression: ');
    readline.prompt();
    
    readline.on('line', (line) => {
      try {
        const result = evaluate(line.trim());
        console.log(`Result: ${result}`);
      } catch (err) {
        console.log('Invalid expression');
      }
      readline.prompt();
    }).on('close', () => {
      console.log('Calculator exited.');
      process.exit(0);
    });
  

With the help of Mathjs flexible APIs, we have created a simple yet powerful calculator that evaluates user-given expressions dynamically.

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