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Anonymous's avatar
Anonymous
Not applicable
7 years ago
Solved

Measuring Distance to find closest point between points from a single table

Hi All,    Hoping someone may know how to include a FILTER to remove itself as a possible answer.    For the example i am trying to find the closest neighbour to a house in a single table, i have...
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  • dedelman_clng's avatar
    dedelman_clng
    7 years ago

    OK, I took AlBs code and Anonymouss last post and turned it into a measure.  First, I recreated 'Route Information' to have 5 dates' worth of data, one date of which is missing 3 of the locations (Dt is literally just a list of 5 dates 1/14 - 1/18):

     

    Route Information =
UNION (
    CROSSJOIN (
        SUMMARIZE (
            'Table2 (2)',
            'Table2 (2)'[MEMNO],
            'Table2 (2)'[Post Code],
            'Table2 (2)'[Lattitude],
            'Table2 (2)'[Longitude]
        ),
        FILTER ( Dt, Dt[Date] < "1/18/18" )
    ),
    CROSSJOIN (
        SUMMARIZE (
            FILTER (
                'Table2 (2)',
                NOT ( 'Table2 (2)'[MEMNO] IN { "A21200", "A22701", "B10500" } )
            ),
            'Table2 (2)'[MEMNO],
            'Table2 (2)'[Post Code],
            'Table2 (2)'[Lattitude],
            'Table2 (2)'[Longitude]
        ),
        FILTER ( Dt, Dt[Date] = "1/18/18" )
    )
)

    Then taking the working code, transformed it into a measure, keeping the Date filter (I'm probably not doing it the most efficient way using variables - I still have trouble getting ALLEXCEPT and KEEPFILTER working without trial and error):

     

    DCH (Miles) =
VAR HouseLatitude = MIN ( 'Route Information'[Lattitude] )
VAR HouseLongitude = MIN ( 'Route Information'[Longitude] )
VAR EarthCircumference = 3959
VAR P = DIVIDE ( PI (), 180 )
VAR House = SELECTEDVALUE ( 'Route Information'[MEMNO] )
VAR __Dt = SELECTEDVALUE ( 'Route Information'[Date] )
RETURN
    MINX (
        FILTER (
            ALL ( 'Route Information' ),
            'Route Information'[MEMNO] <> House
                && 'Route Information'[Date] = __Dt
        ),
        VAR CinemaLatitude = 'Route Information'[Lattitude]
        VAR CinemaLongitude = 'Route Information'[Longitude]
        VAR _DistanceFromCurrentRough =
            80 * SQRT ( POWER ( ( HouseLatitude - CinemaLatitude ), 2 ) +  POWER ( ( HouseLongitude - CinemaLongitude ), 2 )
                )
        RETURN
            IF ( _DistanceFromCurrentRough <> 0, _DistanceFromCurrentRough )
    )

    As you can see, on 1/18/18, the distance is different for M49418

     

     

     

Anonymous's avatar
Anonymous
Not applicable
7 years ago

Hi AlB

 

Yeah i have tried the Calculated column on the full data set and prior to any slicers been applied have managed to verify the distances produced are very close to accurate, 100% accurate enough for what i intend. 

 

Slight issue when we filter the data though, so there is a Date column which will date when these points are relevant or occured over the previous 7 days. 

 

If i filter to only show houses on the 16th January as an example the closest distance remains the same but its closest may be from a house on the 18th January so in this scanario wouldn't be a possible closest. 

 

Based on the conversation i did try creating a caluclated measure with the same formula without much sucsess it doesn't relate to the MEMNO so wont display the values for the closest distance in a table view using the MEMNO. 

 

So it is working from a total dataset view but the information wont update as we filter down for a specific date or only houses with a closest cinema of Doncaster Vue as an example. 

 

How would be make the same working formula work with filtered data, as a measure? 

 

Thanks though from a dataset point of view its great and from what points ive validated is fairly accurate. 

 

Thanks, 

 

Josh

dedelman_clng's avatar
dedelman_clng
Icon for Community Champion rankCommunity Champion
7 years ago

OK, I took AlBs code and Anonymouss last post and turned it into a measure.  First, I recreated 'Route Information' to have 5 dates' worth of data, one date of which is missing 3 of the locations (Dt is literally just a list of 5 dates 1/14 - 1/18):

 

Route Information =
UNION (
    CROSSJOIN (
        SUMMARIZE (
            'Table2 (2)',
            'Table2 (2)'[MEMNO],
            'Table2 (2)'[Post Code],
            'Table2 (2)'[Lattitude],
            'Table2 (2)'[Longitude]
        ),
        FILTER ( Dt, Dt[Date] < "1/18/18" )
    ),
    CROSSJOIN (
        SUMMARIZE (
            FILTER (
                'Table2 (2)',
                NOT ( 'Table2 (2)'[MEMNO] IN { "A21200", "A22701", "B10500" } )
            ),
            'Table2 (2)'[MEMNO],
            'Table2 (2)'[Post Code],
            'Table2 (2)'[Lattitude],
            'Table2 (2)'[Longitude]
        ),
        FILTER ( Dt, Dt[Date] = "1/18/18" )
    )
)

Then taking the working code, transformed it into a measure, keeping the Date filter (I'm probably not doing it the most efficient way using variables - I still have trouble getting ALLEXCEPT and KEEPFILTER working without trial and error):

 

DCH (Miles) =
VAR HouseLatitude = MIN ( 'Route Information'[Lattitude] )
VAR HouseLongitude = MIN ( 'Route Information'[Longitude] )
VAR EarthCircumference = 3959
VAR P = DIVIDE ( PI (), 180 )
VAR House = SELECTEDVALUE ( 'Route Information'[MEMNO] )
VAR __Dt = SELECTEDVALUE ( 'Route Information'[Date] )
RETURN
    MINX (
        FILTER (
            ALL ( 'Route Information' ),
            'Route Information'[MEMNO] <> House
                && 'Route Information'[Date] = __Dt
        ),
        VAR CinemaLatitude = 'Route Information'[Lattitude]
        VAR CinemaLongitude = 'Route Information'[Longitude]
        VAR _DistanceFromCurrentRough =
            80 * SQRT ( POWER ( ( HouseLatitude - CinemaLatitude ), 2 ) +  POWER ( ( HouseLongitude - CinemaLongitude ), 2 )
                )
        RETURN
            IF ( _DistanceFromCurrentRough <> 0, _DistanceFromCurrentRough )
    )

As you can see, on 1/18/18, the distance is different for M49418