Using maps in Power BI is a powerful way to visualize geographical data. Power BI supports multiple mapping options, including Bing Maps, ArcGIS Maps, and Filled Maps. Each of these map types offers unique functionalities to help users gain insights from spatial data. Below is a detailed, step-by-step guide on how to use maps in Power BI:
1. Getting Started with Maps in Power BI
- Before using maps, ensure that you have geographical data available, such as country, state, city, longitude, latitude, or postal codes.
- Make sure your data is clean and has the necessary geographical fields for mapping.
2. Adding Maps to Your Report
- Open your Power BI Desktop and load the dataset that contains geographical information.
- From the Visualizations pane, select the Map or Filled Map icon, depending on the type of map you want to create.
3. Using Bing Maps (Basic Map)
Steps to use Bing Maps:
- Add the Map Visual: Select the Map visual from the visualizations pane.
- Assign Data Fields: Drag and drop your geographical field (like city, state, or country) to the Location field well. If you have latitude and longitude, drag them into the Latitude and Longitude field wells.
- Adjust Data Points: The map will automatically plot your geographical points based on your data.
- Customize Bubble Size: You can use Size to control the size of the bubbles, based on another measure, such as sales volume or population.
- Customize Color: Use Color Saturation to color the points based on a numerical field, for example, profit or revenue.
Additional Features:
- Map Style: In the formatting pane, you can customize the map style (road, aerial, etc.).
- Zoom Level: Adjust the zoom level to focus on specific regions.
- Hover Over Details: When you hover over any location, Power BI will show a tooltip with details from the data.
4. Using ArcGIS Maps for Power BI (Advanced Mapping)
Steps to Use ArcGIS Maps:
- ArcGIS Visual: ArcGIS Maps for Power BI provides advanced map visualization options, including heatmaps, reference layers, and more.
- Enable ArcGIS Maps: In the Visualizations pane, select the ArcGIS Maps visual.
- Add Geographic Data: Drag your geographical fields (like latitude and longitude or place names) into the Location field well.
- Set Other Data Fields: You can also assign other fields such as Size for the radius of the data points and Color for color saturation.
Customization in ArcGIS Maps:
- Reference Layers: ArcGIS maps allow you to add custom reference layers such as political boundaries, roads, or terrain.
- Heat Maps: ArcGIS provides a heatmap visualization, which can be used to identify areas with high concentrations of data points.
- Cluster Data: ArcGIS can cluster points on the map to provide a clearer view of geographic data.
- Map Themes: You can choose from various map themes such as street maps, satellite imagery, and others.
Note: ArcGIS Maps for Power BI requires an ArcGIS Online account, which may require a subscription depending on the features used.
5. Using Filled Maps (Choropleth Maps)
Steps to Use Filled Maps:
- Select Filled Map Visual: Choose the Filled Map from the visualizations pane.
- Assign Data Fields: Drag a geographical field (such as country, region, or state) into the Location field well.
- Use Data for Color: Assign a numerical field (such as sales, revenue, or population) to the Color saturation field well. This will fill the map regions with colors based on the value.
Customization of Filled Maps:
- Legend Customization: You can customize the legend to represent the data range by changing the color scale.
- Region Data Highlighting: This map allows you to highlight regions based on the numerical data, such as using darker colors for higher values.
- Data Labels: You can display data labels on the regions, showing specific values for each geographical area.
- Zoom & Pan: Zoom into specific areas or pan the map to different regions for a more detailed view.
6. Enhancing Map Visuals with Customizations
- Custom Tooltips: Add tooltips to your maps to provide additional information when users hover over a location. Tooltips can display fields like sales numbers, dates, or categories that give context to the data points on the map.
- Themes and Colors: Customize the map appearance with Power BI’s themes. This allows you to make the map more in line with your report’s design. You can change map background colors, border settings, and more.
- Add Shape Files or Custom Maps: In both ArcGIS and Filled Maps, you can upload custom shape files (.shp), GeoJSON, or custom map data if your geographic areas don’t fit standard mapping options.
7. Handling Missing or Invalid Data
- Sometimes, geographical data may not be recognized or may not map correctly. If this occurs:
- Ensure that your data is well-structured (using known locations like city names, postal codes, etc.).
- Consider using a custom geographical field like latitude and longitude if locations are not mapped automatically.
- Use Power BI’s Geocoding feature to resolve addresses into longitude and latitude, or clean up the data manually.
8. Performance Considerations for Mapping
- Optimizing Data: When working with large datasets, map performance can degrade. Reduce the number of points plotted on the map or aggregate the data to represent regions (e.g., using sales by country rather than individual cities).
- Reduce Visual Complexity: Limit the use of multiple map layers or complex maps with many reference points, which may slow down rendering.
- Use Aggregation: For large datasets, consider using aggregation techniques to reduce the number of data points plotted on the map.
9. Interactivity and Filtering
- Slicers and Filters: You can integrate slicers to allow users to filter the map based on categories or time periods (such as filtering by product category or year).
- Drillthrough and Cross-filtering: Enable drillthrough options to allow users to right-click on a map region and get more detailed information, or use cross-filtering to have map selections affect other visuals on the report.
10. Best Practices for Mapping in Power BI
- Use Appropriate Map Type: Choose the correct map type based on your data and objective. Use Filled Maps for regional data, Bing Maps for individual point data, and ArcGIS Maps for more advanced visualizations.
- Minimize Clutter: Avoid overloading maps with too many data points. Use aggregation or data clustering to make maps more readable.
- Consistency with Other Visuals: Ensure that maps are visually consistent with other report visuals (e.g., use similar color schemes, legends, and themes).
- Accessibility: Provide alternative text for map visuals to ensure accessibility for all users.
Summary
Using maps in Power BI allows users to visualize geographical data and gain insights based on location. Power BI offers a variety of map types including Bing Maps, ArcGIS Maps, and Filled Maps, each providing different features and customization options. The steps involve selecting a map visual, assigning geographic fields, and customizing the map’s appearance and interactivity. With proper data preparation, performance optimization, and following best practices, maps in Power BI can significantly enhance data storytelling and decision-making.