Icon Map by Altius

Semi geocoded data in Power BI Maps

Recently encountered a dataset that only partially had latitude and longitude information and observed some strange behaviour that I was unaware before. So I decided I do a little exploration to find out how geocoding works in Power BI.

I will test it on 4 visuals that I most commonly use for mapping. There are others there that might behave differently.

Data

The Data
The Data

The data I used is simple to make it easy to spot difference in behaviour.

Map visual

Let’s start with the most commonly used Map visual first.

Map with Location and Coordinates filled but without size
Map with Location and Coordinates filled but without size

I added City in Location, Average Lat and Long in the Coordinates section and the With Coordinates column to the Legend.

As you can see that only those cities are shown that have coordinates.

This is what I expected and experienced before.

Notice that the Size field is empty currently.

Fields without Size

What happens if I add a measure into size?

With Size
With Size

My initial expectation was that the previous behaviour won’t change.

As you can see that know all the cities are shown.

I started to wonder that what is happening here.

Are all the points are sent to bing to geocode or only those that does not have that information in the data?

Unfortunately the cities currently in the data would be in the right place regardless.

Fields with Size

Let’s add Cambridge to the mix

I had to find a city that was not geocoded correctly by the Bing Map API.

Correctly in this case means: did not found the city I was looking for, but another one in another country.

UK cities are generally a good examples for this because they are more likely to have US or Australian counterparts for some reason. 🙂

One example is Cambridge. So I added one more line to the dataset.

I wanted to try it without using coordinates first just to verify that it shows a different Cambridge.

Cambridge without Coordinates
Cambridge without Coordinates

Once I added a Latitude and Longitude information the city appeared in the right place.

Cambridge with Coordinates
Cambridge with Coordinates

So it seems that the map visual uses the information that are in the data and tries to geocode for the missing values if you have a measure in the size column.

In practical terms it means that this behaviour can be utilized that you only need to provide geocodes for those locations that are not recognized correctly by the Bing Map API.

Filled Map visual

Filled Map with Coordinates
Filled Map with Coordinates

Filled Maps behave differently because they don’t have a size option.

You can add conditional formatting but that does not change this behaviour.

It will still only show the locations that have latitude and longitude information.

If you remove the Latitude and Longitude data, then it will revert back to the Bing Map API and it will show all the cities (some of them potentially not where you want)

ESRI Map visual

Esri Map behaves similar to Filled Maps.

ESRI with Coordinates
ESRI with Coordinates
ESRI without Coordinates
ESRI without Coordinates

Icon Map by Altius

Icon Map is a great visual to do complex geographical analytics, I highly recommend for you to try it out. It was created by James Dales (MVP).

Link to the Visual in AppSource

Icon Map by Altius
Icon Map by Altius

Because this is a custom visual it is a bit different.

It needs geocodes to show points in the map. So it will only work with the already geocoded data.

Hope this blog post gave you some good ideas in mapping.

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About the author

Mihaly Kavasi

Data-driven Decision Making Enthusiast.
Power BI Expert and Trainer. Helping organizations and communities to use data effectively.
Big fan of RE and Electric cars.
Working @ AltiusData

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