Learn how to create spike maps for displaying data values as vertical spikes over geographic areas.
Spike Maps display data from a Spike Height field on defined points of latitude and longitude. Each spike's height is proportional to the data value it represents, creating a three-dimensional effect that makes it easy to identify patterns and outliers across geographic regions.
Spike maps are particularly effective for visualizing phenomena that have a strong geographic component, such as population density, sales volumes, earthquake magnitudes, or pollution levels. The vertical spikes create a striking visual effect that draws attention to areas with high values while maintaining geographic context.
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 Spike Map.
In the Basemap section under the Map tab, you can select an underlying basemap for your map element. The basemap is a map, stored in GeoJSON format, consisting of features (geographical shapes) such as countries, provinces, and electoral districts. In order to add a basemap to a map element, you must first add a basemap to your project. This can be done by selecting New Basemap in the Project tab. Clicking Find Basemap then opens a library of more than 600 basemaps to choose from.
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.
In spike maps, the basemap serves as a background layer, defining the geographic extent of the map container. While the basemap itself is not connected to the overlaid spikes, it establishes the visible area in which the spikes are displayed.
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. In order to add a dataset to a map element, you must first add a dataset to your project. This can be done by selecting New Dataset in the Project tab.
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.
After you have selected a dataset, you can optionally enable the Prefilter Dataset switch, which lets you filter the data that is supplied to the map. The filter is a "prefilter" because it is applied before the visualization is generated; end users are unable to adjust the filter dynamically.
Next, select Latitude and Longitude fields. These are fields (columns) within the selected dataset that will determine the location of each spike on the map element. Both fields must be assigned the Coordinate data type in the dataset editor.
You can establish connections to filter elements under the Map tab, in the Connections section, by making a selection under Filter.
Filter elements display values from a specified Filter Field, in the form of checkboxes, dropdown menu items, or (for numeric filtering) slider values. A given map can be connected to one or more filters, and the same filter can be connected to multiple maps or other elements. Once connected to a map, a filter element will dynamically control the dataset records passed to the map element, based on user selections made on the filter.
For more details about connecting to filters, see the main Maps page.
In the Colors section under the Map tab, you can assign a Color Field from the selected dataset. Choose either a text or numeric field (e.g., number, currency, percent, or measurement). For text fields, each unique value becomes a category that can be assigned a specific color. For numeric fields, you can configure a Color Gradient, set Domain Minimum and Maximum values, and define the Color Scale. Additionally, you can assign a Missing Data Color and adjust the default Opacity.
You can also assign a fixed color to all spikes on the map. This is useful when you only want to vary the spike height while keeping the color consistent.
In the Spikes section, you can configure properties related to the size and appearance of the spikes:
In the Annotations section under the Map tab, you can add annotations consisting of text and/or symbols to your map.
Under Custom, you can add custom annotations by picking a longitude and latitude to place the annotation on the map. You can then choose either or both of the following two options:
Tooltips on maps can be enabled by selecting the Map tab, navigating to the Tooltip section, and selecting Display Tooltip. These are automatically configured to display the series fields you have selected in your map.