topic Re: Calculation distance between latitudes & Longitudes in DAX Commands and Tips

Calculation distance between latitudes & Longitudes

SCHAPELM — Tue, 21 Mar 2023 03:44:25 GMT

I currently want to calculate the distance between two sites based on the lattitude & longitude. The lattitude & longitude are currently contained within the table listed against each site.

How i want it to work

Step 1: Select Site 1

Step 2:Select Site 2

= Result Distance between site 1 & 2

I need help in creating the two measures required for step 1 & step 2 then writing the equasion for the result.

I know the calculation to to work out the distance is:
=acos(sin(lat1)*sin(lat2)+cos(lat1)*cos(lat2)*cos(lon2-lon1))*6371

Im new to power BI but fluent in tableau so i know how it should work in that format but new to DAX

Thanks
Matt

Re: Calculation distance between latitudes & Longitudes

tamerj1 — Tue, 21 Mar 2023 04:22:18 GMT

Hi SCHAPELM
How do you have the locations in your data?
Do you have the latitude and longitude in separate columns or together in one column? please present a sample

Re: Calculation distance between latitudes & Longitudes

SCHAPELM — Tue, 21 Mar 2023 04:26:53 GMT

Hi tamerj1
the latitude and longitude are in seperate columns within the table against each site

below is an example of how it is presented

SiteDescription	Latitude	Longitude
Site 1	-49.22	121.86
Site 2	-38.04	140.67
Site 3	-38.00	140.71
Site 4	-37.94	140.73
Site 5	-37.9	140.56

Re: Calculation distance between latitudes & Longitudes

tamerj1 — Tue, 21 Mar 2023 06:00:45 GMT

SCHAPELM
Thank you.

Please refer to attached sample file with the proposed solution

Distance = VAR FromSite = SELECTEDVALUE ( 'Site From'[From Site] ) VAR FromTable = FILTER ( 'Table', 'Table'[SiteDescription] = FromSite ) VAR FromLatitude = MAXX ( FromTable, 'Table'[Latitude] ) VAR FromLongitude = MAXX ( FromTable, 'Table'[Longitude] ) VAR ToSite = SELECTEDVALUE ( 'Site To'[To Site] ) VAR ToTable = FILTER ( 'Table', 'Table'[SiteDescription] = ToSite ) VAR ToLatitude = RADIANS ( MAXX ( ToTable, 'Table'[Latitude] ) ) VAR ToLongitude = RADIANS ( MAXX ( ToTable, 'Table'[Longitude] ) ) RETURN ACOS ( SIN ( FromLatitude ) * SIN ( ToLatitude ) + COS ( FromLatitude ) * COS ( ToLatitude ) * COS ( ToLongitude - FromLongitude ) ) * 6371

Re: Calculation distance between latitudes & Longitudes

SCHAPELM — Tue, 21 Mar 2023 11:04:02 GMT

Hi tamerj1
Thankyou for this,
just curious as I have plotted all my sites on a map (over 500) is it possible to use the map to autoselect 'Site 1' & 'Site 2' fields in the equasion
In essence you select site 1 from the map, then select site 2 and a card displayed on the report would show the distance. Understand if this is too complex

cheers

Re: Calculation distance between latitudes & Longitudes

tamerj1 — Tue, 21 Mar 2023 11:50:41 GMT

SCHAPELM
Please see attached modified sample file

Distance = IF ( COUNTROWS ( VALUES ( 'Table'[SiteDescription] ) ) = 2, VAR FromTable = TOPN ( 1, 'Table', 'Table'[SiteDescription], ASC ) VAR Lat1 = RADIANS ( MAXX ( FromTable, 'Table'[Latitude] ) ) VAR Lon1 = RADIANS ( MAXX ( FromTable, 'Table'[Longitude] ) ) VAR ToTable = TOPN ( 1, 'Table', 'Table'[SiteDescription] ) VAR Lat2 = RADIANS ( MAXX ( ToTable, 'Table'[Latitude] ) ) VAR Lon2 = RADIANS ( MAXX ( ToTable, 'Table'[Longitude] ) ) RETURN ACOS ( SIN ( Lat1 ) * SIN ( Lat2 ) + COS ( Lat1 ) * COS ( Lat2 ) * COS ( Lon2 - Lon1 ) ) * 6371, "Select two locations" )

Re: Calculation distance between latitudes & Longitudes

Anonymous — Tue, 06 Jun 2023 10:47:22 GMT

Dear all,

i replied your code on my project in order to obtain the distance in kilometers. Unfortunately, the result is not accurate. Is it a data latitud/longitud problem? I'm affraid not bcs I tested it on a website and it recognized the kilometer distance correctly.

Brief:

- on my original database i had repeated coordinates several times since each row is a zipcode;

- I named my site1 as "origem" and remove duplicated coordinates;

- I named my site2 as "destination" and remove duplicated coordinates;
- "admin name3" is location name;
- i already testing removing duplicates in original database but nothing changed;

my measure is:

Distance =

VAR FromSite = SELECTEDVALUE ( Origem[admin name3] )

VAR FromTable = FILTER ( 'Origem', 'Origem'[admin name3] = FromSite )

VAR FromLatitude = MAXX ( FromTable, 'Origem'[Latitude] )

VAR FromLongitude = MAXX ( FromTable, 'Origem'[Longitude] )

VAR ToSite = SELECTEDVALUE ( Destino[admin name3] )

VAR ToTable = FILTER ( 'Destino', 'Destino'[admin name3] = ToSite )

VAR ToLatitude = RADIANS ( MAXX ( ToTable, 'Destino'[Latitude] ) )

VAR ToLongitude = RADIANS ( MAXX ( ToTable, 'Destino'[Longitude] ) )

RETURN

ACOS (

SIN ( FromLatitude ) * SIN ( ToLatitude )

+ COS ( FromLatitude ) * COS ( ToLatitude ) * COS ( ToLongitude - FromLongitude )

) * 6371

Could someone help me? I'm not getting why kilometeres are incorrect. Is due tables relationship? i kept it without any connection as you showed on your summary.

Thank you in advance