You can use a heatmap as a data layer type on a map visualization to identify the density or high concentration of point values or metric values associated with the points. For example, you can use a heatmap to identify the high profit stores in a geographic region or country.
You can create two types of heatmap layers:
- Density heatmap - Uses only map-related column data (such as latitude and longitude columns). Density heatmap layers show the cumulative sum of a point, where each point carries a specific weight. A point has a radius of influence around it, such that other points that fall in the same area also contribute to the total cumulative result of a point.
- Metric heatmap - Uses measure column data in the same layer. For example, if you add a measure column to the Color section on the Grammar Panel the heatmap is updated to show interpolated metric values.
- Create or open the project where you want to use a heatmap layer on a map visualization. Confirm that you’re working in the Visualize canvas.
- Create an empty map visualization.
- Drag and drop attribute columns containing map-related data from the Data Panel to the Category (Geography) section on the Grammar Panel.
- If you’re creating a project with a map visualization, in the Data Panel, right-click an attribute column and click Pick Visualization then select Map.
- Go to the Data Layers tab of the properties pane.
- Alternatively, click Layer options in the Category (Geography) section and click Manage Layers.
- To create a density heatmap, click Layer Type value and select Heatmap.
- Alternatively, you can add a new map layer, change the layer type to Heatmap, then add attribute columns to the Category (Geography) section.
- To create a metric heatmap, drag and drop a metric column from the Data Panel to the Color section. The heatmap visualization changes from density to metric.
- In the Data Layers tab of the properties pane, specify the options for the heatmap layer such as Radius, Interpolation, Transparency, and Color.
- The default interpolation method is automatically selected based on the aggregation rule of the metric column or value that you’ve selected for the layer.
- You can select the radius value in pixels (px). The radius value is the extent of influence of a measure around a point value on a map.