Vega Tutorials

Last updated 3 years ago

Vega Tutorials

These tutorials introduce you to common Vega specification patterns so you can start creating visualizations quickly and easily. Each tutorial uses a code example that demonstrates a particular Vega feature or pattern. The tutorial covers basic Vega concepts and serves as the foundation for some of the tutorials that follow, and introduces you to the API for communication with the backend. Other tutorials provide more in-depth information about specific Vega implementations.

Use these tutorials to gain a better understanding of Vega by experimenting with them to create new visualizations on your own HEAVY.AI system and database. You can also to make adjustments to Vega code and see real-time changes in charts.

For information about the Vega specification syntax and properties, see .

Tutorial Framework

Because the tutorials focus on the Vega specification, they use a simple client implementation that sends the render request to the HEAVY.AI server and handles the response:

Common index.html

<!DOCTYPE html>
<html lang="en">
  <head>
    <title>HEAVY.AI</title>
    <meta charset="UTF-8">
  </head>
  <body>
    <script src="js/browser-connector.js"></script>
    <script src="js/vegaspec.js"></script>
    <script src="js/vegademo.js"></script>

    <script>
    document.addEventListener('DOMContentLoaded', init, false);
    </script>
  </body>
</html>

Common vegademo.js

function init() {
    var conn = new MapdCon()
        .protocol("http")
        .host("my.host.com")
        .port("6273")
        .dbName("heavyai")
        .user("heavyai")
        .password("changeme")
        .connect(function(error, con) {
          con.renderVega(1, JSON.stringify(exampleVega), vegaOptions, function(error, result) {
            if (error) {
              console.log(error.message);
            }
            else {
              var blobUrl = `data:image/png;base64,${result.image}`
              var body = document.querySelector('body')
              var vegaImg = new Image()
              vegaImg.src = blobUrl
              body.append(vegaImg)
            }
          });
        });
}

Finding the Cause of Errors

On a connection error, you can view the error message to determine the cause of the error. To determine the cause of Vega specification errors, catch and handle the renderVega() exception.

Available Tutorials

PreviousVega NextVega at a Glance

Last updated 3 years ago