21 ms·

> doesn't depend on lat/lon (because that has inherent error margins in it). What do you mean by that?

by gloflo 7y ago

atonse 7y ago
To map a particular point (like a house) with latitude and longitude, you have to be accurate to 5 or 6 decimal points. If you have the right data, then yes you absolutely can map this. But if you're taking, say a telemetry point from a truck moving across the city and trying to map it to an address, there's going to be some drift in that number. And you're going to use that coordinate to say "what's the nearest house to this" – but due to that potential drift, you might match with a different house. This is not life or death stuff. But then it becomes harder to "cluster" points together to say "all these datapoint correspond to this house". Having a slightly larger grid system allows you to say "anything in this 100sq foot square will be associated with this house" which allows you to have some margin of error, while still being able to address individual addresses. So then instead of -72.883322, 38.128312 being treated differently from -72.883320, 38.128317, they all cluster around one "square" which makes it easy to just group them. But What3Words is trying to give each of those "squares" a unique english word identifier, whereas other coordinate systems probably just use alphanumeric codes. I didn't know their algorithm was proprietary. That's bullshit because there is no "algorithm" per se – it's just mapping numbers to word lists. That's it. But that's marketing.
- gloflo 7y ago
  You are making point (location) in polygon (building) queries anyways, if I understood you correctly. GNSS can be off, there is not much you can do about this for free. Any other location-description will be the same. You cannot fix GNSS accuracy by using different representation of location. If you just want to snap your coordinates to a grid, check s2 or h3 or just make your own grid in your country's authorative coordinate system or even snap your coordinates to a lower precision. W3W is really dumb.
  - danielscrubs 7y ago
    H3 looks awesome I’ve been searching for a solution to that problem for my hobby project! I wouldn’t say that W3W is dumb. I like the idea as a global mnemonic device. But it is a hard sell.
    - gloflo 7y ago
      I meant dumb as simple in a technological sense. The idea is quite attractive but there are so many problems with their wordlists and algo that I don't consider it a system worth using, even it was not proprietary and unlawfully patented

> doesn't depend on lat/lon (because that has inherent error margins in it). What do you mean by that?

by gloflo 7y ago

> doesn't depend on lat/lon (because that has inherent error margins in it). What do you mean by that?

To map a particular point (like a house) with latitude and longitude, you have to be accurate to 5 or 6 decimal points. If you have the right data, then yes you absolutely can map this. But if you're taking, say a telemetry point from a truck moving across the city and trying to map it to an address, there's going to be some drift in that number. And you're going to use that coordinate to say "what's the nearest house to this" – but due to that potential drift, you might match with a different house. This is not life or death stuff. But then it becomes harder to "cluster" points together to say "all these datapoint correspond to this house". Having a slightly larger grid system allows you to say "anything in this 100sq foot square will be associated with this house" which allows you to have some margin of error, while still being able to address individual addresses. So then instead of -72.883322, 38.128312 being treated differently from -72.883320, 38.128317, they all cluster around one "square" which makes it easy to just group them. But What3Words is trying to give each of those "squares" a unique english word identifier, whereas other coordinate systems probably just use alphanumeric codes. I didn't know their algorithm was proprietary. That's bullshit because there is no "algorithm" per se – it's just mapping numbers to word lists. That's it. But that's marketing.

gloflo 7y ago
You are making point (location) in polygon (building) queries anyways, if I understood you correctly. GNSS can be off, there is not much you can do about this for free. Any other location-description will be the same. You cannot fix GNSS accuracy by using different representation of location. If you just want to snap your coordinates to a grid, check s2 or h3 or just make your own grid in your country's authorative coordinate system or even snap your coordinates to a lower precision. W3W is really dumb.
- danielscrubs 7y ago
  H3 looks awesome I’ve been searching for a solution to that problem for my hobby project! I wouldn’t say that W3W is dumb. I like the idea as a global mnemonic device. But it is a hard sell.
  - gloflo 7y ago
    I meant dumb as simple in a technological sense. The idea is quite attractive but there are so many problems with their wordlists and algo that I don't consider it a system worth using, even it was not proprietary and unlawfully patented