Heat map, a density visualization technique, shows areas of high and low concentration on a map. While a point map with 10’s of thousands of locations can become cluttered, a heat map visualization of the same data can quickly show areas of dense population.
For example, if you plot the locations of all your customers as a heat map, you can quickly see where there are pockets of low or high number of customers.
ZeeMaps provides support for a heat map in both the interactive and print versions. Currently we look at the frequency, or number of points at a given location, to determine the density. Over time we’ll extend this to allow for the density value to be determined through one of the the marker fields.
When combined with the Zip Code Finder tool in ZeeMaps, this can be a great way to quickly determine the zip codes with high density of points on a map.
Example Heat Map
Here’s an example of a map of locations of all the Used Computer Stores in the US. With the heat map, one can quickly see that Boston and New York are the most dense areas, while other major cities like San Francisco, Dallas, etc., have some notable presence as well. If you click on the icon at the top right of the map the display will change to the regular clustered point map.
We can also get an image of the same map, using the menu item Print or Share -> PDF/PNG Image. In the resulting dialog, we check the option for “Heat Map” for the pin style.
Setting a Heat Map in ZeeMaps
To turn on the heat map feature for your map, go to the settings page (menu Map -> Settings). Click on the Map Display tab. Check the box for “Enable Heat Map” and hit Save Changes. Go back to the map and it will turn the visualization into a heat map. There will be a small icon at the top right of the map (see interactive map above). You can click on that icon to toggle the display from a heat map to a regular point map.
Often, it is useful to show continuously updated geo maps. For example, geo maps updated by a large number of field operators. In the field, operators can indicate status change for job sites by changing the color of markers on the geo map. Similarly, crowdsourced geo maps would show updates from the field as new locations are added. For such geo maps, it is often desirable to display the geo map on a large screen, visible to several users and employees to monitor progress. This can also be useful in conferences, e.g., where each attendee marks their location of origin or interest. In classrooms, you can use such geo maps for students to mark their locations.
Manually refreshing the geo map screen every so often becomes tedious quickly. It is much better if the geo map can refresh itself every few minutes.
ZeeMaps allows you to set up your geo map for auto-refresh. Once set up for auto-refresh, you can leave the geo map visible on a browser window and it will automatically refresh itself every five minutes.
Enabling Auto-Refresh for Geo Maps in ZeeMaps
To enable auto-refresh of your geo maps, use the Map -> Settings menu to go the settings page. Click on the Map Display tab in the settings page. Check the box for “Auto-Refresh map markers every 5 minutes”. Hit Save Changes.
To recap, ZeeMaps provides many ways of making changes to geo map markers concurrently by many users. Users can add more locations to a geo map. They change the status of a geo map marker by changing its color. Manually refreshing the geo map on a continuous basis is tedious. ZeeMaps’ capability auto-refreshed every few minutes makes it much easier to setup overview geo maps for a groups of users.
By default, Google Maps scale is displayed at the bottom right of the map in kilometers (or meters at close range), as shown in the diagram below.
If you want to see the Google Maps scale in miles (or feet), you’ll need to click on the scale to switch between kilometers and miles. This is okay once in a while, but can become irritating if you have to do it all the time for your maps.
We’ve added a new customization where you can specify that you want the scale in miles for your map.
To change this setting, use the Map -> Settings menu to go to the settings page on your map menu. Then, click on the Map Display tab, check the box for Use “Miles” scale control, and hit Save Changes. Go back to your map and the scale should now be in miles instead of kilometers.
You can get US Map images from ZeeMaps in different sizes and resolutions, e.g., to print out a wall-poster, or include in a PowerPoint slide.
On your interactive map in ZeeMaps, click the Print or Share -> PDF/PNG Image menu item to get the dialog to customize your image.
The first option in the customization dialog is for selecting the “Geography” of your image. This allows you to choose from one of the following options:
Cover Markers – include all the pins or markers that are placed on the map
Map View – use whatever is visible in the map window currently
Select Area – select an area of the map using a rectangle
US Map- make a US Map (possibly with Hawaii, Puerto Rico and Alaska included)
World Map – map of the world
US Map of Used Computer Stores
Select the option for “US Map” to get an image of a US Map with all your customizations overlay’d on it. For example, here’s an image generated from our Used Computer Stores map, with Alaska and Hawaii excluded:
We can also generate a US Map image with Alaska and Hawaii included:
The images are available as a political map with state boundaries, or as a satellite map:
Finally, if you want, you can highlight certain regions on the map, e.g., below we highlight California and Texas:
In this post, we’ve shown a limited set of samples of US Map generated with ZeeMaps. The image customization dialog contains a whole other set of customizations, e.g., selecting the type of markers on the map, the size and resolution of the image, whether you want the markers labeled or not. We invite you to experiment with the myriad of options and contact us in case you need some assistance.
ZeeMaps allows you to lock the zoom levels on your interactive maps.
Use the Map -> Settings menu item to get to the settings page, and then click on the tab for “Map Display”.
Select the minimum and maximum zoom levels, and hit Save Changes.
Go back to the map, and you’ll notice that the map zoom controls do not allow the map to be zoomed-out below the minimum zoom level, or zoomed-in more than the maximum zoom level.