Locating closest match based on Latitude Longitude

Question

So, I have, on Power BI, 2 tables with no relationship. One table contains Latitude & Longitude, along with dates, of positions tracked. And the other table contains the same coordinates but with names of Stadiums.

What I want to do is find the closest stadium near the tracked position.

Can anyone help me out? Thanks in advance!

Answer 1

First of all, we need to use the Haversine function to calculate the minimal distance.

This is to be added as a calculated column to your tracked table.

Nearest = 
    MINX(Stadiums,
    ROUND(2 * 3959 *
        ASIN(SQRT(
            SIN((Stadiums[Lat] - Tracked[Lat]) * PI()/360)^2 +
            COS(Tracked[Lat] * PI()/180) * COS(Stadiums[Lat] * PI()/180) *
                SIN((Stadiums[Lon] - Tracked[Lon]) * PI()/360)^2)), 1))

In this formula, 3959 is the radius of the Earth in miles.

Now, to match up distances & find the nearest stadium:

Stadium = CALCULATE(MAX(Stadiums[Stadium]),
              FILTER(Stadiums,
                  ROUND(2 * 3959 *
                      ASIN(SQRT(
                          SIN((Stadiums[Lat] - Tracked[Lat]) * PI()/360)^2 +
                          COS(Tracked[Lat] * PI()/180) * COS(Stadiums[Lat] * PI()/180) *
                          SIN((Stadiums[Lon] - Tracked[Lon]) * PI()/360)^2)), 1)
                  = Tracked[Nearest]))

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PS: The values are rounded to avoid not matching from possible floating point errors. It's not really a necessary step.