Bar Maps
Learn how to plot geographic series data in groups of vertical bars.
Overview
Bar Maps display groups of vertical bars on defined points of latitude and longitude. Each bar's height is proportional to the data value it represents, providing a clear way to compare values across different geographic points. Unlike other maps offered in Mappica, bar maps display multiple series fields, allowing the display of several data categories simultaneously at each geographic point.
Bar Maps are particularly useful for comparing quantities or categories across regions in fields like environmental studies, urban planning, and economics. By positioning bars on geographic locations, they provide an intuitive view of the spatial distribution of variables such as air pollution levels, building heights, or sales volumes. The visual height of the bars helps users quickly grasp both absolute and relative differences, making it easier to spot patterns or outliers in a dataset.
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
Bar Map.
Connecting to a Basemap
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 bar 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 bars, it establishes the visible area in which the bars are displayed.
Connecting to Datasets
In the
Dataset section under the
Map tab, 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 group of bars on the map element. Both fields must be assigned the Coordinate data type in the dataset editor.
Finally, select the Series Fields that should be displayed on the map. Each of these fields will appear as an individual bar in the group of bars that is placed at each geographic location.
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 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.
Connecting to Selectors
If you are building a bar map, you can establish a connection to a selector element under the Map tab, in the Connections section, by making a selection under Selector.
Selector elements control which series fields are displayed in connected elements that use a wide data format. Among map types, only
bar maps display series fields using a wide data format, making them the only map type that can be connected to a selector. Selectors can be displayed as checkboxes, dropdowns, or legends. While a map can be connected to only one selector, a single selector can be connected to multiple maps or other elements that use series fields. Once connected, the selector element dynamically controls the dataset fields (columns) passed to the map as series fields based on user selections.
The example below illustrates gross electricity production in selected Western European countries, with bars representing production in 2014, 2018, and 2022. The selector, shown as checkboxes, displays the names of the dataset fields (columns) used as series fields by the connected map. This allows users to dynamically adjust which of these series are displayed.
This bar map of selected Western European countries is connected to a selector element (the checkboxes), which controls the dataset fields (columns) that are used as series fields by the map.
Colors
Use the Colors section under the Map tab to control bar colors. Bar Maps display series data, so colors are assigned to each individual series field. You can also optionally use the Opacity setting to adjust the opacity of all bars in the map.
Bars
Bar, spike, and symbol maps follow a similar structure, allowing you to adjust key properties related to their size and appearance:
- Height: The height of each bar is determined by the values in the Series Fields from the Dataset section under the Map tab. The Maximum Bar Height field sets the bar's height when a series value reaches the Maximum Bar Value. All other values are scaled proportionally.
- Border: You can specify a Border Width for all bars on the map. By default, the border shares the same color as the bar, making it blend in unless the bar's Opacity, set in the Colors menu, is reduced below 100%. Alternatively, you can apply a Custom Border Color, which assigns the same border color to all bars, regardless of their inner fill color.
Annotations
In the Annotations section under the Map tab, you can add annotations consisting of text and/or symbols to your map.
Begin 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:
- Add Text: Add some Text, pick a Color, and specify the Text Position in relation to the chosen longitude and latitude.
- Add Symbol: Choose a Symbol Shape, a Color for the symbol, and a fixed Width in pixels.
