Hi, I’m sharing back with community here (I encourage you to do the same as you come across your own useful Power BI tips and recipes)
In this post, I will share how to create a custom map file to use in Power BI. To start out, add a Shape Map visual to a report in Power BI Desktop:
Once you add this visual you can pick from lots of included maps as well add your own custom map by clicking Add Map.
That's great, but “Where do I get custom maps or better yet how would I create my own map?” you may ask. Lots of organizations need custom maps for sales districts, service areas, and regions that don't always align nicely to states and zip codes.
How to create your own map
Let's walk through the steps to create your own custom maps using Google Maps and a couple open source tools. When we’re done, you will know how to make a professional looking map that works extremely well with Power BI.
Shape Maps in Power BI use a popular map file format called Topojson. I first encountered TopoJson when I worked as a D3.js developer. If you want to learn more about TopoJson/GeoJson you can go here.
TopoJson is a JSON file that can be quite complex and lengthy. While you could code one in notepad, that would be no fun at best.
Luckily Google Maps provides an on-line tool for creating your own custom maps.
Create a custom map in Google Maps
Go to Google Maps, open "Your Places", Maps, and click Create Map. Start drawing your own map over the area of the world you are interested in tracing. I won't go into the details on how to draw a map, but you will find it fairly intuitive and easy. Use the polygon tool to trace around your custom areas.
IMPORTANT: To map data to your shapes in Power BI, you want to name your Polygons EXACTLY as they are in your data. For example, if in your data you have a [Region Name] field and it has a value of "Western Region", you want to name the Polygon shape you drew in Google Maps, "Western Region" if that's the field you will bind to your map's location property.
Once you have a saved map, Export to KML.
Pick your map layer instead of the "entire map" and check these options:
Click Download and Save.
Now that you have a KML file (another type of mapping file that is based on XML) we need to convert it to JSON. We must go through a couple of steps to get it into a format Power BI can use.
KML to GeoJson You can use tools like https://mapbox.github.io/toGeoJson/ to convert KML to GeoJson. In this tool, you cut and paste the contents of your KML file into the KML window and you will get a GeoJson conversion on the right. Save the conversion to your workstation in a file with a .json extension.
GeoJson to TopoJson
We're not done yet. Now that you have a GeoJson file, you need to run this through a couple of conversions to get it to look nice and export to TopoJson. In this example, I'm focusing on getting a custom map of the United States projected as "USA Albers projection" which will, for display purposes, move Alaska and Hawaii and scale them so they can be easily viewed with the other 48 states.
Depending on your map, you need to do a couple of clean-ups before we're ready to save as TopoJson.
To clean up the file, you need to make sure the map is projected as WGS84. To do this, click the Console button (upper-right)
At the command prompt ($), enter the command -proj wgs84
If you want a map in Albers USA projection also enter -proj albersusa
If your shapes render as black, you may want to get a look at the boundaries before finishing. This command will do this for you.
Finally, save the file as TopoJson by clicking export and selecting TopoJson.
Click Export and Save.
We're almost done. I swear!
Open your custom map in Power BI Desktop
Go back to Power BI Desktop and open your custom map in the format properties of a Shape Map visual
Select your previously created TopoJson file. You should now see your map! If you wish, you can play around with the different types of projections.
Last thing you need to do is bind data to your map. If you properly named your polygons in Google Maps, you should be able to assign your appropriate data field to the Location property of the map, and then assign a measure value to the color saturation.
At this point you should now be feeling like a B.I. rockstar and have a strong urge to show your boss the cool Power BI trick you just learned.
Enjoy and remember Power BI's Community is one of the main things that makes Power BI a great tool. Take a tip, leave a tip.
I tried mjfulke method to create a power bi map for Portugal (only the continent for now), but when i import the resulting map into power bi, i noticed that our district reegions were not able to be rendered in power bi desktop witch was a major disapointment 😞 .
Is there something else i have to do in order to be able to have the regions available in the continent to assign data specific to each district/region, with this method you explained ?
The regions have to be part of the shape data itself to be available.
They should be available though for all major countries.
Theres also some strange bug you can encounter when importing regions that needs fixing via mapshaper command line. Just google the bug and "mapshaper command line" there was a tutorial somewhere how to do it.
Don't remember the bug anymore but I encountered it when importing german postal code area data: