Making maps with Google Chart API

A new version of Google Chart API was released last week. The most important change was the removal of the limit on the number of daily requests. I also noticed that a thematic map feature was added, and this is the result after some tweaking hours:

The map above shows the number of Internet user in the world (proportional). Only unclassified choropleth maps are so far supported by the API. Right-click on the image and select Properties to see the URL generating the map image. The URL contains country codes and values for most of the world countries, but the length (1308 characters) is still within the 2083 limit.

You'll find a quick tutorial for making maps with Google Chart API on this page. So far, I find the mapping feature of Google Chart API more suitable for "country highlighting" than for thematic mapping. The maximum size for maps (440 by 220 pixels) is too restrictive, as a world map needs more detail. I also miss a map legend, so the map reader can spot which colours represent high/low values. Still, it's a good start, and a greater advantage of Google Chart API is the possibility to put charts on top of maps.

UPDATE 6 APRIL 2008: A brief tutorial of thematic mapping with Google Charts API

Data source for Internet users: UNdata

Comments

riccardo zilli said…

i guess your elaboration was really good, and the issue of your work as well. have you an introduction-paper that can help me to understand better the thematic maps issue?
i hope to discover more about thematic mapping.
this could be a thematic maps?
http://www.sokwanele.com/map/all_breaches

sorry for my english! :)
riccardo.zilli@yahoo.it
http://riccardozilli.blogspot.com/2008/03/zimbabwe.html

1 April 2008 at 11:40

Bjørn Sandvik said…

Hi,
I recommend the book Thematic Cartography and Geographic Visualization. You can also have a look at this website.

Jeffrey Barke has made a brief tutorial about Thematic Mapping with the Google Charts API.

Hope this helps!

1 April 2008 at 15:52

Anonymous said…

I just put up a map generator that uses the Google Charts API. It makes it a little easier to highlight the countries.

have a look
http://www.29travels.com/travelmap/

10 August 2008 at 19:15

Anonymous said…

The only problem is that the size of 440 by 220 pixels is the maximum available for all maps. This is very small view...

31 October 2008 at 00:12

Anonymous said…

I wish it had more parameters!!!

13 December 2008 at 02:30

Anonymous said…

A great tutorial on creating heat maps with the new Chart API is here: http://s.gavinr.com/hlL2h2

6 January 2011 at 16:49

Creating a WebGL Earth with three.js

This blog post will show you how to create a WebGL Earth with three.js , a great JavaScript library which helps you to go 3D in the browser. I was surprised how easy it seemed when reading a blog post by Jerome Etienne . So I decided to give it a try using earth textures from one of my favourite cartographers, Tom Patterson . WebGL is a JavaScript API for rendering interactive 3D graphics in modern web browsers without the use of plug-ins. Three.js is built on top of WebGL, and allows you to create complex 3D scenes with a few lines of JavaScript. If your browser supports WebGL you should see a rotating Earth below: [ Fullscreen ] To be able to display something with three.js, you need three things: a scene, a camera and a renderer. var width = window.innerWidth, height = window.innerHeight; var scene = new THREE.Scene(); var camera = new THREE.PerspectiveCamera(45, width / height, 0.01, 1000); camera.position.z = 1.5; var rende...

Thematic Mapping Engine

It's time to introduce the Thematic Mapping Engine (TME). In my previous blog posts, I've shown various techniques of how geobrowsers can be used for thematic mapping. The goal has been to explore the possibilites and to make these techniques available to a wider audience. The Tematic Mapping Engine provides an easy-to-use web interface where you can create visually appealing maps on-the-fly. So far only prism maps are supported, but other thematic mapping techniques will be added in the upcoming weeks. The engine returns a KMZ file that you can open in Google Earth or download to your computer. My primary data source is UNdata . The above visualisation is generated by TME ( download KMZ ) and shows child mortaility in the world ( UNdata ). The Thematic Mapping Engine is also an example of what you can achieve with open source tools and datasets in the public domain: A world border dataset is loaded into a MySQL database . The same database contains tables with statistics ...

Creating 3D terrains with Cesium

Previously, I’ve used three.js to create 3D terrain maps in the browser ( 1 , 2 , 3 , 4 , 5 , 6 ). It worked great for smaller areas, but three.js doesn’t have built-in support for tiling and advanced LOD algorithms needed to render large terrains. So I decided to take Cesium for a spin. Cesium is a JavaScript library for creating 3D globes and 2D maps in the browser without a plugin. Like three.js, it uses WebGL for hardware-accelerated graphics. Cesium allows you to add your own terrain data, and this blog post will show you how. Impressed by the terrain rendering in @CesiumJS - with a 10m elevation model for Norway! Farewell Google Earth. pic.twitter.com/RQKvfu2hBb — Bjørn Sandvik (@thematicmapping) October 4, 2014 Compared to the dying Google Earth plugin , it's quite complicated to get started with Cesium. The source code is well documented and the live coding Sandcastle is great, but there is a lack of tutorials and my development slows down when ...

MasterMaps

Search This Blog