text: // units
  
  // load math.js (using node.js)
  const math = require('../index')
  
  // units can be created by providing a value and unit name, or by providing
  // a string with a valued unit.
  console.log('create units')
  const a = math.unit(45, 'cm')
  const b = math.unit('0.1m')
  print(a) // 45 cm
  print(b) // 0.1 m
  console.log()
  
  // units can be added, subtracted, and multiplied or divided by numbers and by other units
  console.log('perform operations')
  print(math.add(a, b)) // 55 cm
  print(math.multiply(b, 2)) // 0.2 m
  print(math.divide(math.unit('1 m'), math.unit('1 s'))) // 1 m / s
  print(math.pow(math.unit('12 in'), 3)) // 1728 in^3
  console.log()
  
  // units can be converted to a specific type, or to a number
  console.log('convert to another type or to a number')
  print(b.to('cm')) // 10 cm  Alternatively: math.to(b, 'cm')
  print(math.to(b, 'inch')) // 3.9370078740157 inch
  print(b.toNumber('cm')) // 10
  print(math.number(b, 'cm')) // 10
  console.log()
  
  // the expression parser supports units too
  console.log('parse expressions')
  print(math.eval('2 inch to cm')) // 5.08 cm
  print(math.eval('cos(45 deg)')) // 0.70710678118655
  print(math.eval('90 km/h to m/s')) // 25 m / s
  console.log()
  
  // convert a unit to a number
  // A second parameter with the unit for the exported number must be provided
  print(math.eval('number(5 cm, mm)')) // number, 50
  console.log()
  
  // simplify units
  console.log('simplify units')
  print(math.eval('100000 N / m^2')) // 100 kPa
  print(math.eval('9.81 m/s^2 * 100 kg * 40 m')) // 39.24 kJ
  console.log()
  
  // example engineering calculations
  console.log('compute molar volume of ideal gas at 65 Fahrenheit, 14.7 psi in L/mol')
  const Rg = math.unit('8.314 N m / (mol K)')
  const T = math.unit('65 degF')
  const P = math.unit('14.7 psi')
  const v = math.divide(math.multiply(Rg, T), P)
  console.log('gas constant (Rg) = ', format(Rg))
  console.log('P = ' + format(P))
  console.log('T = ' + format(T))
  console.log('v = Rg * T / P = ' + format(math.to(v, 'L/mol')))
  // 23.910432393453 L / mol
  console.log()
  
  console.log('compute speed of fluid flowing out of hole in a container')
  const g = math.unit('9.81 m / s^2')
  const h = math.unit('1 m')
  const v2 = math.pow(math.multiply(2, math.multiply(g, h)), 0.5) // Can also use math.sqrt
  console.log('g = ' + format(g))
  console.log('h = ' + format(h))
  console.log('v = (2 g h) ^ 0.5 = ' + format(v2))
  // 4.42944691807 m / s
  console.log()
  
  console.log('electrical power consumption:')
  const expr1 = '460 V * 20 A * 30 days to kWh'
  console.log(expr1 + ' = ' + math.eval(expr1)) // 6624 kWh
  console.log()
  
  console.log('circuit design:')
  const expr2 = '24 V / (6 mA)'
  console.log(expr2 + ' = ' + math.eval(expr2)) // 4 kohm
  console.log()
  
  console.log('operations on arrays:')
  const B = math.eval('[1, 0, 0] T')
  const v3 = math.eval('[0, 1, 0] m/s')
  const q = math.eval('1 C')
  const F = math.multiply(q, math.cross(v3, B))
  console.log('B (magnetic field strength) = ' + format(B)) // [1 T, 0 T, 0 T]
  console.log('v (particle velocity) = ' + format(v3)) // [0 m / s, 1 m / s, 0 m / s]
  console.log('q (particle charge) = ' + format(q)) // 1 C
  console.log('F (force) = q (v cross B) = ' + format(F)) // [0 N, 0 N, -1 N]
  
  /**
   * Helper function to output a value in the console. Value will be formatted.
   * @param {*} value
   */
  function print (value) {
    console.log(format(value))
  }
  
  /**
   * Helper function to format an output a value.
   * @param {*} value
   * @return {string} Returns the formatted value
   */
  function format (value) {
    const precision = 14
    return math.format(value, precision)
  }
  