When a data layer is added, the legend will display information about the current data layer, including the year, variable, geography type, and the value range for each color on the map. The legend also gives you the ability to customize the map by changing any of these aspects.
Year - Depending on the data layer added, you can change the time frame to a different year, quarter, or month.
Variable - Changing the variable will change the type of data displayed on the map. Each data layer has specific and unique variables, which may include the number, percent, median, change across years, or other types of data, depending on the data layer.
Shade By - This gives you the ability to change the geography type at which the current data layer is shaded.
PolicyMap displays data at different geography levels; the zoom level determines what geography type the data on the map is shaded by. For example, when looking at the nation, data is usually shaded by state. As you zoom in, the geography of the shaded data might change to the county, zip code, census tract, and finally block group level (this depends on the availability of data at a given geography type for each data layer). A great place to see what geographies each data layer is available at is the Our Data page.
Source - The top of the legend will display the data source under the name of the layer. Click on the source to see more information on our Data Directory.
Select the X symbol to the left of the data title in the legend to remove the data layer.
Subscriber Features:
Subscribers have the ability to create custom values for the ranges the colors appear in. To customize, click Ranges, and type in the values for each range. When you are done editing your ranges, click Apply to show the custom ranges on the map. Restore Defaults will revert the ranges back to default.
This feature allows a user to define their own ranges for how data is shown on the map. It can be used for any numerical variable in PolicyMap. This is useful when the default ranges don't show variation in predominantly low or high values in a specific area of interest.
Another feature for subscribers is the ability to increase or decrease the number of ranges shown on the map. This is helpful if you want to simplify the ranges of data or if you need to show more complexity in the shading. Also, 2-3 color ranges are better for printing in black and white. This option is available by clicking on Ranges and clicking on the number drop down menu.
Subscribers can also change the color ramp used on the shaded map. If you do not like the default purple color palette, you can choose another.
Remember, when you initially load a thematic data layer on PolicyMap, you will see the default settings so make sure to check the legend for other options to customize the data layer. To read a full guide on all features on PolicyMap, please look at our Primer available here.
If you want to know more about a feature or topic, send your request to info@policymap.com subject "Tutorial Topics."