Pen Settings

CSS Base

Vendor Prefixing

Add External Stylesheets/Pens

Any URL's added here will be added as <link>s in order, and before the CSS in the editor. If you link to another Pen, it will include the CSS from that Pen. If the preprocessor matches, it will attempt to combine them before processing.

+ add another resource

You're using npm packages, so we've auto-selected Babel for you here, which we require to process imports and make it all work. If you need to use a different JavaScript preprocessor, remove the packages in the npm tab.

Add External Scripts/Pens

Any URL's added here will be added as <script>s in order, and run before the JavaScript in the editor. You can use the URL of any other Pen and it will include the JavaScript from that Pen.

+ add another resource

Use npm Packages

We can make npm packages available for you to use in your JavaScript. We use webpack to prepare them and make them available to import. We'll also process your JavaScript with Babel.

⚠️ This feature can only be used by logged in users.

Code Indentation


Save Automatically?

If active, Pens will autosave every 30 seconds after being saved once.

Auto-Updating Preview

If enabled, the preview panel updates automatically as you code. If disabled, use the "Run" button to update.

HTML Settings

Here you can Sed posuere consectetur est at lobortis. Donec ullamcorper nulla non metus auctor fringilla. Maecenas sed diam eget risus varius blandit sit amet non magna. Donec id elit non mi porta gravida at eget metus. Praesent commodo cursus magna, vel scelerisque nisl consectetur et.

              <h1><a href="https://www.freecodecamp.org/challenges/map-data-across-the-globe" target="_blank">Map Data Across the Globe</a></h1>
<h5>Zoom in/out | Hover over the data point for additional data</h5>
<h5><a href="https://youtu.be/dJbpo8R47D0" target="_blank">Watch this tutorial</a></h5>

<div id="map"></div>

<div id="tooltip">
  Name: <span id="name" class="info"></span><br> 
  Nametype: <span id="nametype" class="info"></span><br>
  Fall: <span id="fall" class="info"></span><br> 
  Mass: <span id="mass" class="info"></span><br>  
  Recclass: <span id="reclass" class="info"></span><br>  
  Reclat: <span id="reclat" class="info"></span><br> 
  Reclong: <span id="reclong" class="info"></span><br> 
  Year: <span id="year" class="info"></span>

<!-- Footer-->
<div class="row text-center">
			<div class="col-xs-12">
				<div class="tableFooter">
				  <!-- for footer -->
      <div class="col-xs-6">
      <h5><a href="http://www.eleftheriabatsou.com" target="_blank">Eleftheria</a> | <a href="https://codepen.io/EleftheriaBatsou" target="_blank">Projects</a> | <a href="https://www.youtube.com/channel/UCC-WwYv3DEW7Nkm_IP6VeQQ" target="_blank"> Coding videos </a></h5>
      <!-- social media -->
      <div class="col-xs-6 text-primary">
        <a href="https://twitter.com/BatsouElef" target="_blank">
     <img class="footerSvg"src="https://image.flaticon.com/icons/svg/60/60580.svg" 
      style="text-align:center" alt="twitter"> 
         <a href="https://github.com/EleftheriaBatsou" target="_blank">
     <img class="footerSvg" src="https://image.flaticon.com/icons/svg/25/25657.svg" 
      style="text-align:center" alt="github"> 
        <a href="https://www.youtube.com/channel/UCC-WwYv3DEW7Nkm_IP6VeQQ" target="_blank">
     <img class="footerSvg" src="https://image.flaticon.com/icons/svg/25/25312.svg" 
       style="text-align:center" alt="youtube"> 
    <!-- end footer -->
<!-- end of Footer -->
              body {
 text-align: center;
h1, h3, p{
/* ------------------------------------------ */

path {
  stroke: red;          //Borders color
  stroke-width: 0.5px;  //Borders width line 
  fill: orange;         //Countries color

#tooltip {
  text-align: left;
  padding: 16px;
  background-color: lightsalmon;
  border: 1px solid black;
  width: auto;
  opacity: 0;
  color: black;
  position: absolute;

 * Footer
a:link    {color:orangered;  text-decoration:none}
a:visited {color:orangered; text-decoration:none}
a:hover   {color:red; text-decoration:underline}

  margin-top: 15px;
  width: 32px;
              //We are using d3.js (v3), jquery and topojson (https://github.com/topojson or https://github.com/topojson/topojson)
// TopoJSON is an extension of GeoJSON that encodes topology. Combined with fixed-precision encoding for coordinates, TopoJSON is usually much smaller than GeoJSON.


D3 works with two types of geographic JSON, GeoJSON, and a format called TopoJSON.

GeoJSON vs. TopoJSON
TopoJSON is an extension of GeoJSON that encodes topology. Rather than representing geometries discretely, geometries in TopoJSON files are stitched together from shared line segments called arcs.


$(document).ready(function() {
  // Width and Height of the whole visualization
  var w = 1000; 
  var h = 480;  
  //D3 has some internal functionality that can turn GeoJSON data into screen coordinates based on the projection you set. This is not unlike other libraries such as Leaflet, but the result is much more open-ended, not constrained to shapes on a tiled Mercator map.1 So, yes, D3 supports projections.
  var projection = d3.geo.equirectangular()
  // Create GeoPath function that uses built-in D3 functionality to turn
// lat/lon coordinates into screen coordinates
  var path = d3.geo.path()
  //add the following to create our SVG canvas.
  var svg = d3.select('body')
    .attr('width', w)
    .attr('height', h)
    .attr('width', w)
    .attr('height', h)
    .attr('fill', 'white');
  // Append empty placeholder g element to the SVG
  // g will contain geometry elements
  var g = svg.append("g");
  //add a call to d3.json to load the TopoJSON file
  //so it loads into our visualization
  d3.json('https://d3js.org/world-50m.v1.json', function(error, data) {
    if (error) console.error(error);
      .datum(topojson.feature(data, data.objects.countries))
      .attr('d', path);
    //create the zoom effect
    var zoom = d3.behavior.zoom()
      .on("zoom", function() {
        g.attr("transform", "translate(" +
          d3.event.translate.join(",") + ")scale(" + d3.event.scale + ")");
          .attr("d", path.projection(projection));
    // Load the data from the json file
    d3.json('https://raw.githubusercontent.com/FreeCodeCamp/ProjectReferenceData/master/meteorite-strike-data.json', function(error, data) {
      if (error) 
      var locations = data.features;
      var hue = 0; //create the circles
      // we will pass our data (the TopoJSON) as an argument, then create SVG elements using a classic D3 append. Selecting all paths, the TopoJSON is bound in the data method. From here, we can perform work on each element.
      locations.map(function(d) {  // Create an object for holding dataset
        hue += 0.36                // Create property for each circle, give it value from color
        d.color = 'hsl(' + hue + ', 100%, 50%)';
      // Classic D3... Select non-existent elements, bind the data, append the elements, and apply attributes
        .append('circle') //show the circles
        .attr('cx', function(d) {
          if (d.geometry) {
            return projection([d.geometry.coordinates[0], d.geometry.coordinates[1]])[0];
        .attr('cy', function(d) {
          if (d.geometry) {
            return projection([d.geometry.coordinates[0], d.geometry.coordinates[1]])[1];
        .attr('r', function(d) {
          if (d.properties.mass) {
            return Math.pow(parseInt(d.properties.mass), 1 / 9);
        .style('fill', function(d) {
        //Use the Color Function to set the Fill Value for each circle
          return d.color;
      //Next, we need to write two pieces of code, one that listens for when the value of the tooltip changes, and one that updates the SVG elements.
      //We are going to use some D3 code to listen for an input change on the tooltip elements
      //Add Event Listeners | mouseover
        .on('mouseover', function(d) {
          d3.select(this).style('fill', 'black'); 
            .style('left', (d3.event.pageX + 20) + 'px')
            .style('top', (d3.event.pageY - 80) + 'px')
            .style('display', 'block')
            .style('opacity', 0.8)
        //Add Event Listeners | mouseout
        .on('mouseout', function(d) { 
          d3.select(this).style('fill', d.color);
            .style('display', 'none');
🕑 One or more of the npm packages you are using needs to be built. You're the first person to ever need it! We're building it right now and your preview will start updating again when it's ready.