4 ms·

Seems like reinventing a solid wheel with a disposable one... I'm more for Latitude and Longitude: - Latitude/Longitude have been around for a long time, estab

Seems like reinventing a solid wheel with a disposable one... I'm more for Latitude and Longitude: - Latitude/Longitude have been around for a long time, established, proven reasonably reliable. - Ultimate more calculable, no need for lookup/conversion - No language issues (three words seem to be primarily English) also unless it becomes an international standard whats to stop someone making a similar service with different words... - Latitude/Longitude could be added to map legends (even with decimals, it still is quite understandable) - Letter codes can be more confusing then a general numeric coordinate, get one letter wrong and you are off the map and not sure which letter is the one. I use Lat/Lon in my apps and can't see how these would make things more efficient or as independent on external resources. They all seem much more arbitrary. (edited for formatting)

dwyerm 7y ago
You are fortunate that lat/long is sufficient for your use-case. In my experience, the problem is that it isn't as exact as you'd think, especially when your measurement passes back and forth between reality, the idealized cartesian lat/long, and node/distance understandings of road networks. At a previous company, our map provider moved the entire United States three meters to the west and we spent the next week re-adjusting endpoints that were suddenly in medians, on overpasses, etc. tl;dr: Nothing's easy.
- LarryMade2 7y ago
  Yeah had that happen on google maps API a few years back where the earth adjusted southeast or something like that... I wonder if the offset you experienced was able to be re-adjusted by calculation or was the new geometry inconsistent? Ive realized we can't ever get exact - best we can hope for is finding something that's constant enough for a long period. So far lat/lon has done best.
  - dwyerm 7y ago
    In retrospect I also wonder why we didn't just do a bulk update. I think the problem was that we discovered the geocoding problem and started correcting for it before we understood where the problem was actually coming from. By the time we discovered it was a simple constant offset, we'd already damaged our own data with the one-off fixes. Worse, the offset was right there in black-and-white in the release notes that we failed to read. By the way, I apologize for being flippant about it. Location is just one of those things -- like time -- that too many people think is simple, but actually has devilish details that bite the unwary. You are fortunate that lat/long is sufficient and I hope you remain wary.
jandrewrogers 7y ago
You need to specify latitude/longitude as a specific relationship relative to a specific reference surface. Polar coordinates alone are insufficient for consistent addressing. For example, you could specify the latitude/longitude be interpreted as geodetic coordinates relative to the WGS84 ellispoid, neither of which will always be true when working with unspecified polar coordinates.
fyfy18 7y ago
I agree, however this and latitude longitude don't fully solve the problem the post discusses. Just because you know where the entrance is, it doesn't describe how to get there. Maybe the area isn't available on mapping services (not that uncommon for small communities, even in Western countries) or maybe you need to take a specific route to get there.
- LarryMade2 7y ago
  I was thinking that it would be cool to have some AR thing going (ala Pokemon Go - virtual arrow pointing toward the destination) But of course that fails if there is no direct route from where the traveler is. To get directions working right. I think there needs to be a good open standard for road/pedestrian maps, but that will only be as good/reliable as the data source... Haven't looked into open street maps but I think that would be one to check out.

dwyerm 7y ago

You are fortunate that lat/long is sufficient for your use-case. In my experience, the problem is that it isn't as exact as you'd think, especially when your measurement passes back and forth between reality, the idealized cartesian lat/long, and node/distance understandings of road networks. At a previous company, our map provider moved the entire United States three meters to the west and we spent the next week re-adjusting endpoints that were suddenly in medians, on overpasses, etc. tl;dr: Nothing's easy.

LarryMade2 7y ago
Yeah had that happen on google maps API a few years back where the earth adjusted southeast or something like that... I wonder if the offset you experienced was able to be re-adjusted by calculation or was the new geometry inconsistent? Ive realized we can't ever get exact - best we can hope for is finding something that's constant enough for a long period. So far lat/lon has done best.
- dwyerm 7y ago
  In retrospect I also wonder why we didn't just do a bulk update. I think the problem was that we discovered the geocoding problem and started correcting for it before we understood where the problem was actually coming from. By the time we discovered it was a simple constant offset, we'd already damaged our own data with the one-off fixes. Worse, the offset was right there in black-and-white in the release notes that we failed to read. By the way, I apologize for being flippant about it. Location is just one of those things -- like time -- that too many people think is simple, but actually has devilish details that bite the unwary. You are fortunate that lat/long is sufficient and I hope you remain wary.

jandrewrogers 7y ago

You need to specify latitude/longitude as a specific relationship relative to a specific reference surface. Polar coordinates alone are insufficient for consistent addressing. For example, you could specify the latitude/longitude be interpreted as geodetic coordinates relative to the WGS84 ellispoid, neither of which will always be true when working with unspecified polar coordinates.

fyfy18 7y ago

I agree, however this and latitude longitude don't fully solve the problem the post discusses. Just because you know where the entrance is, it doesn't describe how to get there. Maybe the area isn't available on mapping services (not that uncommon for small communities, even in Western countries) or maybe you need to take a specific route to get there.

LarryMade2 7y ago
I was thinking that it would be cool to have some AR thing going (ala Pokemon Go - virtual arrow pointing toward the destination) But of course that fails if there is no direct route from where the traveler is. To get directions working right. I think there needs to be a good open standard for road/pedestrian maps, but that will only be as good/reliable as the data source... Haven't looked into open street maps but I think that would be one to check out.