Issue Using Shape Map with Non-Contiguous Regions

[GinoPicozzi]

Hi All,

I am trying to build a custom shape map using the Nielsen Designated Marketing Areas, and have run into an issuing rendering non-contiguous regions.  I started by converting a GeoJSON file to TopoJSON using mapshaper (https://mapshaper.org/).  I then used this TopoJSON file with the shape map feature in Power BI, and ran into the following rendering issue:

To the best of my knowledge, all of the missing regions share the common trait of having non-contiguous parts -  Like the Los Angeles DMA (including coastal islands) (The following maps are from a third-party site, for reference):

Or the unique Devner DMA:

At first, I thought the issue may have to do with mapping regions defined by multiple arcs, but this is not the case as the Salt Lake City DMA rendered correctly (and is defined by over 30 arcs in the TopoJSON file):

Has anyone run into this issue before (or have an idea of how to solve it)?  Any advice is greatly appreciated.

Best,

Gino

[v-xicai]

Hi @GinoPicozzi ,

You can refer to the likes  : https://community.powerbi.com/t5/Desktop/Problem-using-custom-shape-map/td-p/55795/page/2

https://www.sqlshack.com/create-geographic-maps-power-bi-using-custom-shape-maps/

https://docs.microsoft.com/en-us/power-bi/visuals/desktop-shape-map

Best Regards,

Amy

[GinoPicozzi]

Hi @v-xicai ,

Thank you for sharing this.  The article was very helpful in getting a better understanding of shape maps.  While it was not able to solve my rendering issue, it helped to uncover some further information.

In the example you shared, the original file was a .shp file within a .zip folder.  Using this entire .zip folder, mapshaper was able to create a topojson file that properly renders non-contiguous regions.  My starting file is in a geojson format.  After digging a little further, I noticed that the topojson file created from the .zip folder in your example uses MultiPolygons for non-contiguous regions (like the UK), and Polygons for contiguous regions (like Bulgaria).  The topojson file created from my geojson file, uses Polygons for both contiguous and non-contiguous regions.  This seems to be the underlying cause of the rendering issue.  Would you say that is accurate?

Thanks again for your help on this,

Gino