How to create a Filled Map?
What is a Filled Map?
Filled Maps are maps that have polygon shapes defined by the geographical borders (i.e. country's border, state's border), and each shape will contain a different color based on the value it carries.
Follow the example below to learn how to set up a Filled map.
- For demonstration purposes, we will try to visualize the number of COVID-19 cases in the US by states. We will use real data from The New York Times' article.
- We have already downloaded the data and uploaded it to this Google Sheet link (updated 27th July 2020)
- Import data from the Google Sheet link into Holistics. For more information, see How to import data.
Creating a Filled Map
To create a Filled Map, select the filled map icon from the visualizations pane.
In the Viz settings, drag and drop your location field into Location. Right after you drag the field inside, a dropdown will expand, asking you to assign a specific location type for that field. This is not optional. However, we recommend you doing that to improve the precision of the map. Read more here: How to improve map precision in Holistics.
In our example, we'll select State/Province for our field State.
Your location data should be in the form of full-text country names or abbreviation. For more information, see Supported location formats.
If you click on Get results, you will see that all the locations are colored light orange by default.
If you want to change the global color or set another color to each location, go to Styles, select your location field, click on the square colored box beside each location to change it.
Depending on what you do next, you will be able to generate two different types of maps:
- If you put a value into the Value field, you'll generate a choropleth map.
- If you put a dimension into the Legend field, you'll generate a distribution map.
Choropleth Map (Beta)
Choropleth Maps are Filled maps but the regions are colored based on a numerical value, most typically ratio data like per-capita income or population density.
To generate a Choropleth Map, you need to input your location data into the Location field, then a value into the Value field. Then click Get results.
If you want to change the color scale (make it smooth, change min-max values, change the number of steps), navigate to Styles, select Color formatting, and configure here.
Color formatting options
Set color by...: Select a field to color your map. After you have selected a field, the following options will appear.
- Style: Click on the color scale to change the color style of the map. Choose Smooth to generate a color gradient for both the map and the scale. Choosing Steps to explicitly divide the color scale into color blocks, each of which will contain a range of values. For example, if our data ranges from 0-100, and we set 5 steps, there will be 5 corresponding blocks of color: 0-20, 20-40...
- Min - Mid - Max: by default, these fields' values will be set to Auto. However, you can select from the drop-down list to the left of the input field to change to Number or Percent. Then, you can type your own data and the changes will be applied immediately to the color scale in Style.
Note: If your input data in min-max is out of range (i.e. your data range is 1-100 but you input 101 in min), Holistics will choose the max color as the displaying color. If your input data in mid is out of range (i.e. you put 1000 in mid), Holistics will not make any change to the color scale.
Distribution Map (Coming soon)
Distribution Maps are Filled maps but the regions are colored based on a string value, most typically a subject such as an animal, religion, or political parties.
Custom Maps are designed to support dataset that contains geographical data type that Holistics has not supported (i.e. Zipcode, Counties, districts, wards...) (see more: Supported location formats)
Learn how to create custom map like the map of Alabama's counties' population below.
Improving map precision
Sometimes, Holistics will not recognize one or more of the location names in your data.
When this happens we will display a small notice modal on the lower right of the preview window. Hovering on this will help you understand which location names we failed to recognize.
This may happen if there is a location or abbreviation that Holistics does not recognize, mostly because of typos, wrong formats, or the fact that such location exists in 2 different places (i.e. "Paris" is both the city of France and the city of Texas, USA)
To improve the map precision, see How to improve map precision in Holistics.