Miles are wrong in exported activities file

[Y-crosscountry-in-July]

The mile calculations are often wrong in the exported activities file.   E.g., in the following row, 2014-1018 !=2.  The total was a 10% undercount in 98 drives.  Thanks.

Drive

7/22/2021 12:21 AM

7/22/2021 12:24 AM

2 min

2

xx

yy

57%

55%

1018

1024

Tesla

[Y-crosscountry-in-July]

Correction, it should be 1024-1018!=2

[Sofia-ABRP]

Hi @Y-crosscountry-in-July,

At the moment we calculate the driven distances using the location data sent by your vehicle throughout a drive. We are unfortunately not able to access the mileage of the car itself.

Last week we increased how frequently we are able to get location data from Tesla vehicles. This should have improved the accuracy of the calculated distances of drives in the "My drives" page and in exports.

Please note that if the internet connection of an area is bad we might still get too few data points from your vehicle. This will in turn result in jumps between data points which will be interpreted as shorter distances than what was actually driven (will appear as very straight lines in "My drives"). There's little we can do to improve the accuracy of the data if that's the case. Thank you for your understanding.

/Sofia

[Y-crosscountry-in-July]

Thanks for the explanation.  I'm familiar with the problem of estimating total distance from a set of (possibly noisy) waypoints.  I hadn't realized that's how you get the total.

I was also guessing a possible problem if the internal addition was done with too few significant digits, and the rounding wasn't done right.  This is a known numerical issue when adding a large number of small numbers.

I'm confused about you not being able to get the car's milage date, since the spreadsheet also gives odometer readings.  Or, are they not what they seem to be?

Finally, how do I get the detailed track log?   I don't think many people (any people?) have driven what I just did (almost 4000 miles through the US southwest and south in a Tesla) and would like to plot it.

Thanks.

[Katya-ABRP]

Hi @Y-crosscountry-in-July,

As Sofia described, this is how it is done currently. That being said, the precision of the distances in the summary could absolutely be improved, despite missing data points since we do get the mileage. We'll be looking into this!

Regarding 'detailed track log', do you mean like a summary of all the driving segments at once?

/Katya