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Mapcode – A short address for any location on Earth

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Re: Mapcode – A short address for any location on Earth

#91

Post by digikata »

lstamour wrote: post #60
diydsp wrote: post #30

Earlier quoted context omitted.

> latitudes/longitudes, unless we're talking about shortening their representation. That's a much smarter idea than this mapcode system. It would make sense to replace the base-10 representation with base 36.... at least in the Roman alphabet. It would probably be smarter to pick a base that works with the world's alphabets. Oh yeah, not all the world uses alphabets! But even then, it's not that huge of an improvemen…

From their developers' doc: > Mapcodes can be easily translated between several different alphabets. The default system is based on the roman alphabet. Mapcodes in other alphabets are generated by character substitution. And it's not based on representation of lat/lng, which is why it's more of an improvement: > As explained in the previous section, by reserving short codes for the most densely populated areas, mapco…

Between this, and discussion of hardcoded magic values in lookup tables in the code, I wonder about how future population/geography shifts will be handled. It's not a dealbreaker, but it seems like a technical cost of interpreting mapcodes would be periodic required updates of the translation codes.

Re: Mapcode – A short address for any location on Earth

#92

Post by lstamour »

cabalamat wrote: post #82
lstamour wrote: post #56

Earlier quoted context omitted.

Actually it's that those MapCodes are incomplete. They're missing the country/state designation. If you look up "Ireland 0C.T4" or "US-AK 0C.T4" you should get the correct results. I'll cite a .doc file here, it's also available on the Developers page: > 1. Codes only need to be accurate enough for public, every-day use. At the human scale, when you are within a few meters of a destination, you are “there”. > 4. Peop…

> Actually it's that those MapCodes are incomplete. They're missing the country/state designation. If you look up "Ireland 0C.T4" or "US-AK 0C.T4" you should get the correct results. Imagine if a URL resolved to different addresses in each country you were in. Would that be a better system than what we have now, or a worse one? I think it would self-evidently be worse. I'm surprised they didn't make mapcodes a global…

They did, it just doesn't suit the purpose they had: quick entry into GPS systems; it's true URLs or QR codes would work too, though nothing's stopping such a resolver service from popping up, except of course that non-phone GPS systems probably don't have cameras yet.

> Finally, on top of any and all national mapcodes a location may have, it also always has a 9-letter, context-less map code.

But that's too long to use every day... It would be like requiring all streets to have globally unique names. Because they're qualified by location, you could, if you wanted to, enumerate all matches in order of distance, and in 90% of cases, that would be the location you're looking for. Better here, since many cities will have the same street names in multiple places ;-)

Re: Mapcode – A short address for any location on Earth

#93

Post by cwp »

cabalamat wrote: post #82
lstamour wrote: post #56

Earlier quoted context omitted.

Actually it's that those MapCodes are incomplete. They're missing the country/state designation. If you look up "Ireland 0C.T4" or "US-AK 0C.T4" you should get the correct results. I'll cite a .doc file here, it's also available on the Developers page: > 1. Codes only need to be accurate enough for public, every-day use. At the human scale, when you are within a few meters of a destination, you are “there”. > 4. Peop…

> Actually it's that those MapCodes are incomplete. They're missing the country/state designation. If you look up "Ireland 0C.T4" or "US-AK 0C.T4" you should get the correct results. Imagine if a URL resolved to different addresses in each country you were in. Would that be a better system than what we have now, or a worse one? I think it would self-evidently be worse. I'm surprised they didn't make mapcodes a global…

Globally-unique identifiers make sense on the web, where "going" to a website being served from the other side of the world is as easy as one served from across the street.

That's not true for navigation in the physical world. If you're sitting in Nebraska, how often do you have to navigate to a location in Mongolia? Approximately never! Map codes are optimized for the common case, where you want to go to a location that's nearby.

In fact, it's even more clever than that, since it defines "nearby" as a political unit. Borders may be artificial, but they're real, and crossing them has practical implications. If you're planning to buy something in another jurisdiction, there might be tax implications. You may need your passport to cross the border. You may not speak the language of that area. All of this means that having the political unit as a human-readable part of the map code is useful.

Finally, consider that some URLs do resolve differently depending on where you are. They're called relative URLs. They're very handy and very common. I'd guess that the vast majority of URLs on the web are relative. MapCodes work the same way. The code "Ireland 0C.T4" is globally unique. If you're already in Ireland, you can omit the territory, much as you would omit the country when inviting a friend to your house for dinner.

For cases where you really do have to travel to the other side of the planet, is it really so onerous to specify "Mongolia 0C.t4"?

Re: Mapcode – A short address for any location on Earth

#94

Post by frankus »

Alupis wrote: post #74
lstamour wrote: post #67

Earlier quoted context omitted.

Goal #3 on their list was: > A conversion need not just be based on formulae. A respectable amount of data may be used as part of an algorithm. Which is why when you go to the downloads page, you'll find sources in C, JavaScript and Java, but they all include "data tables". There are a few other restrictions, though it's somewhat unclear how relevant they are here without inspecting the tables closer: > One such limi…

Hmm, I just took a look at their Java SDK... (clearly just sample code, but intended for embedding into your project to get going quickly) They make a lot of assumptions, and a lot of hard-coded values. For example, they seem to have lots of city names and country names hard-coded into a giant String array. ISO country codes are hard-coded (probably a safe assumption so-long as new countries are not added), many "mag…

81.JW4 is a lot easier to tell someone over the phone or transcribe from a business card or billboard, and it's pretty unlikely that the US-AK part would be ambiguous in those contexts. And if it is, a simple "which 81.JW4 did you mean?" would probably disambiguate pretty effectively.

Re: Mapcode – A short address for any location on Earth

#95

Post by cwp »

davexunit wrote: post #89

I don't like this. From what little I have read, mapcodes appear to be proprietary, despite advertising a "free, open standard". >Mapcodes are free. They can be used by anyone, and may be supported, provided or generated by anyone, as long as this is done free of charge, conditions or restrictions Why can't someone charge money for a service that generates mapcodes? >The mapcode algorithms and data tables may not be…

There's quite a bit of territory between "proprietary" and "free software, as approved by the FSF". If the MapCode sources are free for any purpose except confusing people, I'm fine with that.

Re: Mapcode – A short address for any location on Earth

#96

Post by justincormack »

davexunit wrote: post #89

I don't like this. From what little I have read, mapcodes appear to be proprietary, despite advertising a "free, open standard". >Mapcodes are free. They can be used by anyone, and may be supported, provided or generated by anyone, as long as this is done free of charge, conditions or restrictions Why can't someone charge money for a service that generates mapcodes? >The mapcode algorithms and data tables may not be…

Certainly not compatible with Debian free software guidelines.

Re: Mapcode – A short address for any location on Earth

#98

Post by grey-area »

jisaacso wrote: post #29
grey-area wrote: post #14

Objections: 1. This mapcode is country specific (!) 2. Many locations need altitude or fine lat,lon differences to differentiate them (e.g. blocks of flats, offices). 3. What's wrong with altitude, lat and lon on a given projection which can be as precise/imprecise as you want? IMO it'd be better to have a hash of lat,lon,altitude which was globally unique for each level of precision. A system like this needs to be g…

There exists a hash of lat, long globally unique for each level of precision, a geohash [1]. One common application utilizes a space filling Hilbert curve to define an arbitrary precision bounding box around a set of coordinates. You can see an example hash [2]. [1] http://en.wikipedia.org/wiki/Geohash [2] http://geohash.org/9q8yyvfekk8h

I reckon you need to include latitude as well, or it's not really going to be useful for specifying position in cities.

Re: Mapcode – A short address for any location on Earth

#99

Post by frankus »

I, for one, really like this.

* It doesn't use postal codes, which aren't really intended for use for anything but mail delivery and occasionally make that painfully apparent (such as when the boundaries are changed)

* It doesn't depend on street addresses, so it works in countries where the streets aren't reliably or intelligibly named/numbered. It also works in places where there are no streets.

* It's smarter about allocating code space than something like a 10:10 code, since e.g. not a lot of people live in the middle of the ocean (and they can always use a "fully-qualified" MapCode).

* It's super easy to read to someone over the phone, or type in from a business card, or transcribe from a sign.

A couple of uses immediately spring to mind:

* Telling an Uber/Taxi/rideshare where to pick you up when you don't have GPS/data.

* Telling a delivery drone where to deliver your package (without having to correctly remember dozens of digits of lat/long).

* And of course what it was designed for, entering a navigation location quickly.

I'm sure there are some implementation flaws, which may or may not be fatal, but I think it's pretty great.

Re: Mapcode – A short address for any location on Earth

#100

Post by quantized »

drsintoma wrote: post #4

So what's the upside of this vs Geohash? http://en.wikipedia.org/wiki/Geohash

Pros of MapCodes vs. Geohashes:

* MapCodes are shorter by 200-300% for a given accuracy level, assuming each MapCode is prefixed by a two-letter country code for clarity.

Cons of MapCodes vs. Geohashes:

* MapCodes only offer one accuracy level, of apprx. 100 m^2 regions, whereas a Geohash can be arbitrarily accurate.

* MapCodes do not guarantee persistence. They can be redefined at any time, for any reason, at the sole discretion of the project designer, leaving you with a nonreferential or falsely referential code.

* MapCodes do not encode location data within the code, so access to the server is required at all times. If you lack internet access, or if the service is DDoSed, hacked, goes out of business, etc. your codes become useless.

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