Calculating the norm of a vector in Javascript

gistbook.json

{"title":"Calculating the norm of a vector in Javascript","author":"jmeas","pages":[{"pageName":"","sections":[{"type":"text","source":"Determining the norm of a vector can be daunting :fearful: But after you've read this exercise you'll be a pro at it :+1:\n\nThe norm of a vector is its length. In two dimensions, the norm of a vector \\(\\vec{v}\\) can be calculated with the following equation:\n\n$$\\lvert v \\rvert = \\sqrt{x^2+y^2}$$\n\nIn Javascript, we could write a function to calculate this like so:"},{"type":"javascript","source":"var math = require('mathjs');\n\nfunction norm(x, y) {\n  return math.sqrt(math.square(x) + math.square(y));\n}"},{"type":"text","source":"Let's take a look at how we can use this to calculate the norm of a vector \\(\\vec{v} = [3, 4]\\)"},{"type":"javascript","source":"var val = norm(3, 4);\n\n// Set it to the output div\ndocument.getElementsByClassName('output')[0].innerHTML = val;"},{"type":"html","source":"<!-- This is a div to show our output -->\n<div>The norm of our vector is: <span class='output'></span></div>"},{"type":"css","source":"/* Let's give it some styling, too */\ndiv {\n  background: #fafafa;\n  border: 1px solid #ddd;\n  padding: 20px;\n}"}]}],"public":true}