5 ms·

Notably missing from the evaluation is MGRS, the coordinate system used by NATO for more or less the same purpose. I like it because if you have the coordinate

Notably missing from the evaluation is MGRS, the coordinate system used by NATO for more or less the same purpose. I like it because if you have the coordinates of a landmark, you can easily estimate the coordinates of other nearby locations entirely in your head, and the system encodes precision so you can indicate uncertainty. https://en.wikipedia.org/wiki/Military_Grid_Reference_System https://en.wikipedia.org/wiki/Military_Grid_Reference_System

ssambros 7y ago
With it's pros being the ability to know how close the points are just having the 2 coordinates and arbitrary precision. Who knows how far away epic.region.music and epic.global.music are from just the names? While 18SUJ2163104440 and 12SVC0452723150 are 6 grid zones apart east to west.
- 9nGQluzmnq3M 7y ago
  That's a handy property for the 3 people on Earth who have the algorithm behind it memorized, but the rest of the world would prefer to be able to easily read, write and share the codes.
  - labster 7y ago
    Most people can tell proximity in lat/lon coordinates based on the algorithm they learned in first grade: the number line. Perhaps they could use a similarly ubiquitous system, like the alphabet. There’s even a song to help you memorize it!
  - AWildC182 7y ago
    The algorithm is absolutely trivial -> https://en.wikipedia.org/wiki/Military_Grid_Reference_System https://en.wikipedia.org/wiki/Military_Grid_Reference_System It's actually quite pleasant to use and allows you to just truncate to the level of precision you want. S/He just posted the 1m resolution string when 18-SU-J-216-044 would get you to 100m. All this said, I think the real issue is that we refuse to PICK a standard and so every device with a GPS and ever map has one or two of -MGRS -UTM (almost identical to MGRS) -LL DD MM' SS.ss" -LL DD.dddd... -LL DD MM.mmmm...' etc. If you make a device that can output or accept a location string, make sure it can handle all LL cases and UTM/MGRS.
    - dmix 7y ago
      I think we have different definitions of trivial. Or you put a lot of trust in the average persons intelligence or more importantly laziness.
PLenz 7y ago
Mgrs is also a perfect m-ary tree, it really has so many useful properties for doing spatial machine learning.
slavik81 7y ago
To expand a bit, I wish it was included in the comparison not only because it has some big advantages, but also because it has some drawbacks worth examining. The top-level zones are its weakness. The further apart two coordinates are from each other, the more difficult it is to reason about their relationship. MGRS works fantastic for reasoning about coordinates on the same grid square, but gets harder as you move up to comparing between grid squares and harder still as you compare between zones. A grid square is 100km x 100km, so it's pretty big, and coordinates in the square are easy to manipulate. If you know your office is at 4QFJ 21631 04440 and the Starbucks is about 500 meters down the road to the north, then you know Starbucks' coordinates are roughly 4QFJ 21631 04940. To indicate your uncertainty, you'd say 4QFJ 216 049, or possibly just 216 049 if the grid square was already known from context. The system is typically extended to allow that reasoning to work even at the edges of a grid square, by allowing eastings and northings that extend past the grid square edge. This means there's more than one possible way to describe a location, though only one canonical way. Unless you're already familiar with the area, you may need a map to compare coordinates on different squares. Some of the grid zones are also a little oddly shaped. It's mostly not a big deal because they're huge, and it really only affects which coordinate representation is the canonical one at the boundaries, but it would be nice if the top-level 6° by 8° grid zones were more regular.

ssambros 7y ago

With it's pros being the ability to know how close the points are just having the 2 coordinates and arbitrary precision. Who knows how far away epic.region.music and epic.global.music are from just the names? While 18SUJ2163104440 and 12SVC0452723150 are 6 grid zones apart east to west.

9nGQluzmnq3M 7y ago
That's a handy property for the 3 people on Earth who have the algorithm behind it memorized, but the rest of the world would prefer to be able to easily read, write and share the codes.
- labster 7y ago
  Most people can tell proximity in lat/lon coordinates based on the algorithm they learned in first grade: the number line. Perhaps they could use a similarly ubiquitous system, like the alphabet. There’s even a song to help you memorize it!
- AWildC182 7y ago
  The algorithm is absolutely trivial -> https://en.wikipedia.org/wiki/Military_Grid_Reference_System https://en.wikipedia.org/wiki/Military_Grid_Reference_System It's actually quite pleasant to use and allows you to just truncate to the level of precision you want. S/He just posted the 1m resolution string when 18-SU-J-216-044 would get you to 100m. All this said, I think the real issue is that we refuse to PICK a standard and so every device with a GPS and ever map has one or two of -MGRS -UTM (almost identical to MGRS) -LL DD MM' SS.ss" -LL DD.dddd... -LL DD MM.mmmm...' etc. If you make a device that can output or accept a location string, make sure it can handle all LL cases and UTM/MGRS.
  - dmix 7y ago
    I think we have different definitions of trivial. Or you put a lot of trust in the average persons intelligence or more importantly laziness.

PLenz 7y ago

Mgrs is also a perfect m-ary tree, it really has so many useful properties for doing spatial machine learning.

slavik81 7y ago

To expand a bit, I wish it was included in the comparison not only because it has some big advantages, but also because it has some drawbacks worth examining. The top-level zones are its weakness. The further apart two coordinates are from each other, the more difficult it is to reason about their relationship. MGRS works fantastic for reasoning about coordinates on the same grid square, but gets harder as you move up to comparing between grid squares and harder still as you compare between zones. A grid square is 100km x 100km, so it's pretty big, and coordinates in the square are easy to manipulate. If you know your office is at 4QFJ 21631 04440 and the Starbucks is about 500 meters down the road to the north, then you know Starbucks' coordinates are roughly 4QFJ 21631 04940. To indicate your uncertainty, you'd say 4QFJ 216 049, or possibly just 216 049 if the grid square was already known from context. The system is typically extended to allow that reasoning to work even at the edges of a grid square, by allowing eastings and northings that extend past the grid square edge. This means there's more than one possible way to describe a location, though only one canonical way. Unless you're already familiar with the area, you may need a map to compare coordinates on different squares. Some of the grid zones are also a little oddly shaped. It's mostly not a big deal because they're huge, and it really only affects which coordinate representation is the canonical one at the boundaries, but it would be nice if the top-level 6° by 8° grid zones were more regular.