Symbols and Heatmaps in the Google Maps API

The Google Maps API provides a robust platform in which you can add geographical context to your data in a variety of ways. Data visualization is therefore one of the elements at the heart of the Maps API, and today we’re introducing two new techniques for visualizing your data in flexible and dynamic ways.

Symbols

At SXSW Interactive in 2011, I attended a session on geotemporal data visualization that made me keen to make it easier for Maps API developers to build visualizations similar to those discussed. For this reason I’m particularly excited to introduce a simple, yet powerful, new concept to the Maps API v3 that we call Symbols.

Unlike the image icons currently used for marking locations on a map, a Symbol is defined as a vector shape. The size, stroke width, color, and opacity of the shape, are all set by the Maps API application and can be dynamically modified. A small number of shapes, such as a circle, are provided by the Maps API, and custom shapes can be expressed as an SVG path.

Symbols open up a wide range of compelling new possibilities for data visualization and visual effects. For example, the below map illustrates the expansion of the Walmart chain of stores between 1962 and 2006:

In addition to using symbols to represent point features you can also decorate polylines with Symbols. One or more symbols, such as an arrowhead, can be placed at fixed positions on the polyline or repeated along the polyline. Because the polyline that has been decorated does not need to be visible, this feature can also be used to created dotted or dashed polylines, and just as the style of the symbols can be dynamically modified, so too can their location on the polyline:

Heatmaps

Developers often ask how they can represent large amounts of data on a map. Improvements in web browser technology have increased the number of markers that can be rendered by a Maps API application, but above a certain threshold the density of markers can overwhelm the user.

An alternative approach is to use a heatmap, and to enable this approach we’re launching support for browser rendering of heatmaps by the Maps API using the new Heatmap Layer. Your Maps API application can define the colour spectrum, intensity range, and behaviour of the heatmap when the map is zoomed. Here’s the Walmart example from above, but this time visualized as a heatmap:

If you have any technical questions about these new features, we recommend engaging with our developer community online, or joining our regular Google Maps API Office Hours. If you’re at I/O come see us in person at Office Hours in the Google Maps developer sandbox.

 

The New updates in Google Maps/Google Earth APIs Terms of Service

As the Google Maps APIs continue to grow and evolve, we periodically review the Google Maps/Google Earth APIs Terms of Service, which define the terms under which we offer these APIs to developers. Today we are posting an update to these terms which contains a number of notable changes. These changes are intended to encourage use of the APIs in mobile applications, and secure the long term future of the APIs as location aware applications become ever more ubiquitous.

Developers are now permitted to use the Static Maps API outside of a web browser, for example to add thumbnail maps to mobile applications, providing the map image is linked to Google Maps. Developers of mobile apps that are sold for a fee through an online store such as the Android Market and Apple App Store no longer require a Google Maps API Premier license. This brings the Terms of the web based Maps APIs into line with the Terms of the Android Maps API and iOS SDK.

There are also a number of changes that relate to advertising and usage limits. To ensure that we can continue to offer the Maps APIs to developers for free, we now require that any new Maps API applications going forward display any advertising delivered in the maps imagery, unless the site concerned has a Google Maps API Premier license. The opt-out from displaying such advertising that was offered in earlier versions of the Terms will continue to apply to any existing Maps API applications. Information on exercising this right of opt-out will be provided on this blog at least 90 days prior to the launch of any such advertising.

We are also introducing transaction limits on the number of maps that may be generated per day by commercial Maps API web sites or applications. These limits are documented in the Maps API FAQ and will take effect on October 1st 2011. Commercial sites that exceed these limits may be required to purchase additional transactions or a Maps API Premier license. Additional transactions will be offered online at an affordable rate which will be published on or before May 2nd 2011.

Commercial sites that consistently exceed these limits and do not purchase additional transactions online will be contacted by a Maps API Premier Sales Manager to discuss their licensing options. Not for profit applications and applications deemed in the public interest (as determined by Google at it’s discretion) are not subject to these limits. In addition, Non-profits are also encouraged to check out their eligibility for the Google Earth Outreach program.

In addition to the most notable changes detailed above, there are many other minor changes and clarifications, and we therefore recommend that you read the complete Terms and the Google Maps API FAQ. You can also discuss the Terms with other Maps API developers on the Google Maps API forum. Please note that Google’s Developer Relations team, who monitor the forums, are not able to offer legal advice. However any frequently asked questions or areas of confusion will be clarified in future FAQ and Terms updates.

Google Maps API/Google Earth APIs Terms of Service Updates

As the Google Maps APIs continue to grow and evolve, we periodically review the Google Maps/Google Earth APIs Terms of Service, which define the terms under which we offer these APIs to developers. Today we are posting an update to these terms which contains a number of notable changes. These changes are intended to encourage use of the APIs in mobile applications, and secure the long term future of the APIs as location aware applications become ever more ubiquitous.

Developers are now permitted to use the Static Maps API outside of a web browser, for example to add thumbnail maps to mobile applications, providing the map image is linked to Google Maps. Developers of mobile apps that are sold for a fee through an online store such as the Android Market and Apple App Store no longer require a Google Maps API Premier license. This brings the Terms of the web based Maps APIs into line with the Terms of the Android Maps API and iOS SDK.
 


 

There are also a number of changes that relate to advertising and usage limits. To ensure that we can continue to offer the Maps APIs to developers for free, we now require that any new Maps API applications going forward display any advertising delivered in the maps imagery, unless the site concerned has a Google Maps API Premier license. The opt-out from displaying such advertising that was offered in earlier versions of the Terms will continue to apply to any existing Maps API applications. Information on exercising this right of opt-out will be provided on this blog at least 90 days prior to the launch of any such advertising.

We are also introducing transaction limits on the number of maps that may be generated per day by commercial Maps API web sites or applications. These limits are documented in the Maps API FAQ and will take effect on October 1st 2011. Commercial sites that exceed these limits may be required to purchase additional transactions or a Maps API Premier license. Additional transactions will be offered online at an affordable rate which will be published on or before the 2nd May 2011.

Commercial sites that consistently exceed these limits and do not purchase additional transactions online will be contacted by a Maps API Premier Sales Manager to discuss their licensing options. Not for profit applications and applications deemed in the public interest (as determined by Google at it’s discretion) are not subject to these limits. In addition, Non-profits are also encouraged to check out their eligibility for the Google Earth Outreach program.

In addition to the most notable changes detailed above, there are many other minor changes and clarifications, and we therefore recommend that you read the complete Terms and the Google Maps API FAQ. You can also discuss the Terms with other Maps API developers on the Google Maps API forum. Please note that Google’s Developer Relations team, who monitor the forums, are not able to offer legal advice. However any frequently asked questions or areas of confusion will be clarified in future FAQ and Terms updates.