Grid Maps

Learn how to create grid maps for displaying data values in a regular grid pattern over geographic areas.

Overview

Grid Maps display data values in a regular grid pattern, where each grid cell represents a specific geographic area and is colored or styled based on the data values. This approach provides uniform spatial representation and makes it easy to compare values across different regions.

Grid maps are particularly useful for normalizing geographic areas of different sizes, ensuring that smaller regions are as visible as larger ones. They're excellent for electoral maps, demographic data, and any scenario where equal visual weight should be given to different geographic units regardless of their physical size.

Setup

After inserting a map, navigate to the Map tab in the right panel. In the Setup section, you can assign basic properties to the map, which are detailed on the Maps overview page. Next, open the Map Type section and click on Grid Map.

Connecting to a Basemap

In the Basemap section under the Map tab, you can select an underlying basemap for your map element. For grid maps, the basemap defines the regions that will be represented as grid cells.

Pro

If you are on the Pro plan, you can upload your own files (in GeoJSON format) to use as basemaps, by clicking New Basemap, then Upload Basemap.

Connecting to Datasets

In the Dataset section, you can select the dataset for your map element, which contains the data that you wish to display on the map. Your dataset should include fields that correspond to the regions defined in your basemap.

Pro

If you are on the Pro plan, you can upload your own files (in csv format) to use as datasets, by clicking New Dataset and then Upload Dataset.

Join Fields

For grid maps, join fields are essential as they connect the data in your dataset to the geographic regions in your basemap. Select the field in your dataset that corresponds to the region identifiers in your basemap.

Connecting to Filters

You can establish connections to filter elements under the Map tab, in the Connections section, by making a selection under Filter.

Filter elements allow users to dynamically control which data is displayed on the grid map based on their selections.

Colors

In the Colors section under the Map tab, you can assign a Color Field from the selected dataset. For grid maps, colors typically represent the data values, with different colors or color intensities corresponding to different value ranges.

You can configure:

  • Color Gradient for numeric data
  • Categorical Colors for text-based classifications
  • Domain Minimum and Maximum values
  • Missing Data Color for regions without data

Grid Configuration

In the Grid section, you can configure how the geographic regions are arranged in the grid:

  • Grid Layout: Choose how regions are positioned in the grid
  • Cell Size: Adjust the size of individual grid cells
  • Spacing: Set the spacing between grid cells
  • Border Width: Configure borders around grid cells

Annotations

In the Annotations section under the Map tab, you can add text labels or symbols to provide additional context for your grid map.

Tooltips

Tooltips on grid maps can be enabled by selecting the Map tab, navigating to the Tooltip section, and selecting Display Tooltip. These will display the data values and region information when users hover over grid cells.