Talk:Main Page

An archive of "done" items on this page can be found on Talk:Main Page/Archive. Use {{archive}} in edit summaries when archiving a section of the main Talk page.

• Use Template:Graticule on graticule pages for generating a map of the graticule and providing links to surrounding graticules.

Conventions

You might want to come up with some basic conventions and outline them very clearly, very quickly. This site is going to explode pretty quick, and without any, it will become a mess.

EG:

- Region/Graticule pages named "City Name, Country" where "City Name" 
    is the most major (by population) urban center contained within it.
- Activity pages named "YYYY-MM-DD GRATICULE"
- Graticules referred to by top-left coordinate.
- Hell, create a template for region/graticule pages so they have some semblance 
    of consistency. And some sort of outline on what it should contain
- (Descr of region, image of graticule, Activities Section, Notable Events Section).

Should states be abbreviated or spelled out in the list of graticules on the Region/Graticule pages? Currently is a hodgepodge and the OCD in me is cringing. --KDinCT 20:14, 21 May 2008 (UTC)

Just my $0.02. NuclearDog 10:20, 21 May 2008 (UTC)

I think I like the first options best, makes searching (through Special:Allpages, especially) considerably easier. Working on Eindhoven, Netherlands right now. Also it might not be a bad idea to keep discussions on upcoming meetings to the talk pages. Nazgjunk 14:23, 21 May 2008 (UTC)

I personally just wanted to add that we need to set a convention on how the locations are listed. I personally liked them ordered by latitude and longitude (east to west and north to south) but they appear to be recently edited into alphabetical order. Which I do not think is as 'smart' because they are listed by only one city in the area and someone might accidentally add the area again using a different city. Once the list is long duplicates will be hard to spot.--h[User:KDinCT|KDinCT]] 15:19, 21 May 2008 (UTC)

The list of graticules on the Main Page gets this right, doesn't it? That is, the instructions are there. Execution of those is PEBKAC, of course. Nazgjunk 15:22, 21 May 2008 (UTC)

This has since been fixed back into locational order. --KDinCT 15:32, 21 May 2008 (UTC)

In most cases, though, these are sorted NtoS and then WtoE. In many cases, it would make much more sense to sort WtoE first because we already do that mentally with time zone divisions. --Tim P 22:58, 23 May 2008 (UTC)

Graticules should be named by their lower right corner since the algorithm adds to the graticule's integer, right? Actually... it would be: (Lower right in NW Hemi, Lower left in NE Hemi, Upper right in SW Hemi, Upper left in SE Hemi.) That seems a lot for a convention, but all you have to say is "graticules are areas with the same integer coordinates." --TLP 15:30, 21 May 2008 (UTC)

I noticed that this convention causes the name of the graticule to not match the link. Is that an issue? --Scooter 18:32, 21 May 2008 (UTC)

Yeah I just saw that too, but only in some places. Dublin is linked from the bottom left, Bremen is linked from the bottom right. 9i would think it would be reversed, but it's not...) --TLP 21:38, 21 May 2008 (UTC)

What should the convention be when a main city is split (ex. 61, -149(or -150) (Anchorage, Alaska) and 41, -96 West of 56th St; 41, -95 East of 56th St. (Omaha, NE))? My view is that these areas should be seperated and one will get visited sometimes and the other will get visited other times.--KDinCT 15:32, 21 May 2008 (UTC)

What if in a case like that, you have a city page that links to the individual graticule pages in the area? For now, you'd still leave the graticule pages on the main page. I'm thinking over this problem too for Philadelphia -- the city is basically on top of (40, -75) so there's 4 graticules in the area, only one of which I've named Philadelphia. --TLP 15:52, 21 May 2008 (UTC)

I'd say in your case, for example, the same Philadelphia link should be listed four times (once per graticule) on the Main Page. The target page will explain the multigraticule situation, and maybe any locality-specific ways you handle individuals perhaps using more than one. —Christian Campbell 18:58, 21 May 2008 (UTC)

Yeah that could work maybe. It definitely would for just two graticules, but I wouldn't want to put four of them on one page, especially since the NE one in this case includes Staten Island and lower Manhattan. --TLP 21:40, 21 May 2008 (UTC)

In graticule pages, I suggest using the following template: {{graticule |map=<map lat="37" lon="-122"/> |e=East Bay, California |ne=Sacramento, California }} Zigdon 02:08, 22 May 2008 (UTC)

Saturday Times

Um the blog post says the meet ups are at 4, the wiki says they are at 3, is one time more official?

We were still going back and forth and the wiki hadn't been updated. For now, 4:00 -- closer to dinner :) Xkcd 06:55, 21 May 2008 (UTC)xkcd

What happens if the meeting point and me end up in different time zones? This is a particularly serious problem for those who live near the International Date Line, where it deviates from the 180° meridian. I guess the most natural way would be to define that the meeting time should be 4:00 according to the destination's local time, but as far as I can see, this is nowhere defined --62.20.90.195 10:54, 21 May 2008 (UTC)

Well, if you arrived according to your local time, people from either side of the International Date Line would arrive at different times. So it seems sensical for it to be the meeting time according to the destination's local time, as you said. -- 212.219.57.58 11:55, 21 May 2008 (UTC)

That still leaves a problem near the date line: there could be two consecutive Saturday meetings, one on either side of the date line, or there could be no Saturday meeting at all, because one day, the meeting point could be on the side where it is Friday, and the day after, on the other side, where it then is Sunday. The problem is that the date is not clearly defined in a region that is divided by the date line. I doubt it will be a problem in reality though, as the date doesn't seem to run over land, so any region that it runs though will have one side that is completely in the ocean. If we'd just agree to use the local time at the meeting point as the time reference, the whole time line problem is solved, I think. - Sparky

Um, the IDL deliberately avoids crossing nations internally, and I suspect that there aren't that many corner cases where the differing time zone becomes a problem. 192.43.227.18 14:10, 21 May 2008 (UTC)

Perhaps it would be a good idea to have the meetings at lunchtime (say, 12:30 local time), so that people who have to work on weekdays (or Saturday, for that matter) can still go to meetings during their lunch break if it happens to be close enough to where they work. - Sparky

What about weekday meetup times? Should that also be 1600 since people who work won't have time to attend weekday meetings anyway. If I had to set a meetup time, I'd say 6:30pm, which gives enough time after work to get to the place and isn't too late. --waq

Nearby Points?

I forgot to mention that the algorithm doesn't necessarily find the point closest to your present location. Ofcourse, the user can manually select the other regions around his location to find the closest meeting point, but it would be nice if the google earth app would show the 4 closest locations. That way, the chance of meeting different people is greater, because any user would be in 9 regions instead of just one. This could also be useful if the closest point in unreachable, where the user could choose to go to the next closest meeting point. - Sparky

Well, it depends ... generally you'll have one population center surrounded by fairly empty areas. I think we'll be able to better answer this question after a week's experience. --Xkcd 07:46, 21 May 2008 (UTC)xkcd

That, also, depends on where you live. The distance between two closest points horizontally or vertically is approximately 111km. The Netherlands is barely 200km wide. Especially in the western part of the country, which is the most densely populated, cities are rarely more than 15km apart. - Sparky

The thing with having one region is that you get to meet with the same people each time, which could be a good thing - since otherwise, you don't know who you're going to see again. (Though that could be seen as a plus, of course.) My region includes most of London, so in my case I'm probably going to get more people coming to the meet in my region than I am if I was to go to whatever was the closest on the particular day. - Kira. (74.52.15.98 13:16, 21 May 2008 (UTC))

This is most excellent, I know I'm participating! -Sir_Lewk

Would it be possible to include the route-planning feature in the map? For those without navigation systems, that would be very useful. - Sparky.

I'm from Australia, is there any chance of this being implemented in the Pacific Region as well? It sounds like a great idea. - Zorg

This does work for the Australian Region. I'm in Sydney, as of July I'm getting on board --Phraedus 10:20, 21 May 2008 (UTC)

Two thoughts for improvements:

• Maybe use a smaller step size ? If you do not own a car then the destination can be unreachable. Also in Europe (where i am) the polpulation density is in general higher, so one grid cell might encompass two major cities.

We discussed this quite a bit -- currently, the average driving distance is something like 45-50 miles. But if you're trying to have an xkcd meetup for your city, it'd only compound the problem of cities being split up. Half your friends would go to one and half to another. It's already bad enough in DC and Chicago. --Xkcd 09:12, 21 May 2008 (UTC)xkcd

This, ofcourse, strongly depends on the population density (or actually, the XKCD reader density). If you make the regions smaller, the chance of 2 or more people meeting there decreases. As people fail to meet, they stop trying, further reducing the change of a successful meeting for those who try at a later date. - Sparky.

And L.A., Pittsburgh, Philadelphia, Denver... - Cahlroisse

• 45-50 miles is too much for nonprofessional cyclists, are we encouraging petrol burning? Too bad for the ecosystem :P 80.36.82.38 10:01, 21 May 2008 (UTC)

I agree with your point about encouraging petrol burning, however, at some (maybe most) places, such large grid size is needed to have any significantly non-zero chance of meeting somebody. The problem seems to be that there is no clear one-size-fits-all grid size. Implementing a variable grid size sort of eliminates the elegance of the algorithm. Maybe this is just a stage we have to go though; you come up with a simple idea, which grows ever more complicated as it's developed, until you end up with a simple solution - Sparky.

• I'd propose a cell size proportional to the population density. I agree it undermines elegance and simplicity, but sometimes (most of the times?) simpler solutions are just not satisfactory. Besides, seeing the cell sizes changing along with the local population density has a coolness of its own. --80.36.82.38 14:35, 21 May 2008 (UTC)

The ecological implications of petrol burning aside, i just don't have a car ;-) But I agree with you. To allow actual meetings to happen, you need a big grid size, especially in the beginning. -Mucki

I don't have a car either, because I far prefer a motorcycle. I don't really see any options that would enable the use of public transportation without sacrificing to many other properties of the proposed system. I'm afraid the only thing you can do is wait until the meeting point is within a reachable distance. If you can travel 20km in any direction (by bicycle, for example), about 9.8% of the meeting points will be within your range. - Sparky

Perhaps the solution should include people developing their own cell sizes on the city pages to allow for better distribution based on population. For example I can see that there might well be demand enough for both a San Francisco city based cell (based entirely within the city limits) and a larger cell that would include the surrounding areas. At present the cell for SF includes the penninsula far more than it includes the city and has a rather large amount of water as well. Since we have such a high degree of population density, however, it would likely not be a problem to cause such splits. Clearly the issue that's really raised here is that a one-size fits all approach based on pure geography without regard for population is not necessarily the best one. - Belgand

• I think the algorithm should include the base coordinates (the integer portion of your gps location, or maybe even some secret number?) in the hash, otherwise the meetup points form a regular grid, offset by a fixed value from the base coordinates. - Mucki

I don't really see why that's a problem. In fact, it has a couple benefits -- if one coord is all the way to the north of a graticule and you're at the south end, it means the coord in the graticule to the south will be close to you. --Xkcd 09:12, 21 May 2008 (UTC)xkcd

I'd agree; I don't see what's wrong with a regular grid of possible meeting locations, while the upside is that the nearest location is at most 1.4 * 111 / 2 = 78.5km away (half the diagonal of a 111 * 111 square), assuming it is reachable, ofcourse. - Sparky.

I just thought I should add something: this is, ofcourse, only true on the equator, because the distance between the medians reduces as one moves away from the equator. - Sparky

Well, it is not really a problem in itself, but I find that a very regular spacing of the points somehow diminishes the beauty it gets from being otherwise completely random and unpredictable. -Mucki

I would agree with that, however, this does guarantee that there is a meeting point relatively close to you (regardless of reachability).

Except if you live on the Greenwich meridian, and then occasionally the shortest distance will be an entire box-width west or east. And if you live in the N-S centre of a graticule, this maxes out as the diagonal of a 111 * 111/2 rectangle, or 124km. (sucks to live at 0,0... in the ocean south of Ghana...) In the UK, it's more like 111 * 67, an 87km diagonal.

Oddly, where I live (Boreham, Chelmsford, Essex, UK), apparently whatever day it is, I should be meeting in the exact same place in the Thames estuary (I've tried about 5 different dates). Is there something amiss?91.107.26.104

It seems to be working fine. Different coordinate for every day this past week in the 51, 0 (east) graticule that contains Chelmsford. Any more details on the problem? --Xkcd 09:24, 21 May 2008 (UTC)xkcd

hi there, about one thid of my sector is covered with water. are you going to do any sea/ocean detection?

Could I suggest adjusting the main wiki page to say if your meetup is covered by water, click on the next closest square away from the water? Might solve some problems --Phraedus 10:20, 21 May 2008 (UTC)

This may have been covered already, but i'm confused about how the center of mass calculation is working. No doubt a cost function of some kind, but the question is why land mass isn't taken into account, or so it would seem! For example: where i am (Southampton, Hampshire, UK) the center of pass seems to be somewhere in the ocean. Now i realise this is probably due to the isle of white right below southampton. Possible solution, if the area covered by the center of pass holds more than...i don't know...40% water, adjust some variable to force a reduction in granularity. Mainly because the geohashes for the past 4 days have been in the middle of the sea and the reason is clearly just the odds given the amount of water in southampton's center of mass. Also, i've got a python implementation of this appy going, but i don't have access to the center of masses, though this might be me just being silly. Are these available somewhere in a handy dandy XML format?, cheers - SinJax

The squares are the zones bounded by latitude and longitude lines, nothing more. This means the configurations are sub-optimal for some cities, and there will be various conventions for dealing with those.

Oh i see! Talk about over complicating things in my mind :). And the lat/long for each square is the center of the square i assume? or what? Also is it cool if i use the dow data avaiable at http://irc.peeron.com/xkcd/map/data/ for my python implementation directly? or should i contact another webservice somewheres? SinJax

The boundaries of the zones run along the exact longitude and latitude lines closest to your location. - Kira. (74.52.15.98 13:20, 21 May 2008 (UTC))

I live nearly on top of a confluence (northeast of Indianapolis). Would you say that I could choose one of four grid areas, so that I don't have to travel too far? Halcyone1024

Pittsburgh is annoyingly (or beneficially) split down the middle(the very middle 40.441419, -79.977292)

People here have a point about population density. In some places in the world everyone has a car, but in other places a lot of people don't. I almost think that separate areas should have entirely separate rules or something. But again it all depends on how complicated it should be. It could be super simple like it is now and work okish, or be super complicated and maybe work better or maybe not. Personally I currently live in the middle of nowhere so there aren't enough people to make it work, even if we were willing to drive quite a ways and use large graticules. I have also lived in other places where car ownership is low and for most people on most days the meeting point would be out of reach. - forest

Polar coordinates?

I've played a bit with the map, and found out that my town, Freiburg, is right at the edge of a grid (48°000), and that the grid is fairly large. An alternative implementation could use city centers as fixed points and calculate polar coordinates (distance and angle) from the "random" seed. -- tillwe 132.230.104.57 10:02, 21 May 2008 (UTC)

I think this issue is deeper mate. It would seem that the grid implementation is remarkably unsatisfactory when it comes to places in europe and especially england, however, a random distance from city centers wouldn't work very well in sparse areas like america. Some concept of centre of population is required here. SinJax

The problem with living near an edge is non-existent, I think. The maximum distance to the closest point is always half the length of the diagonal of a grid cell. - Sparky

I think we should try to preserve the simplicity and elegance of the algorithm, which, in it's basic form, relies on only 3 pieces of information: the date, the random seed (stock exchange), and the integral part of your location. Adding information like databases of population density would completely ruin it, if you ask me. You might as well include information about computer use and the percentage of the population that can read english, as there are things that strongly influence the XKCD reader density. - Sparky

Maybe we could use a smaller grid size, and have a convention that in more scarcely populated areas, only the even numbered ones are used, or use the ones closest to city centers or something. We don't have to deal with all the cases in the calculation algorithm, we could have the user execute part of the "algorithm". However, the idea is that the user can't really choose where to go. If the user has any control, it should be limited (at the moment, the user can ofcourse choose any of the ~40000 reachable points on the planet) - Sparky

Good call that sounds workable, fixes the problem in southampton anyways :) SinJax

Python-CGI-JSON-o-Rama implementation

Hey so i've made a python version of the reference implementation that returns a JSON parseable object containing the lat/long when given a date, xloc and yloc. It uses the XKCD cache of dow values. I'll put it online in the next 5 mins :D

Here it is, fairly simple actually, hope someone finds it useful :)

Update: I've tried to make it classify the region recommended for a particular day using the euclidian distance of the colour of the image provided by Google Maps

The code is on the link above, tell me what you think :)

SinJax

Cool! I was thinking of making it act as a web service, but for reference implementation it's more important to be simple than useful :) Zigdon 14:53, 21 May 2008 (UTC)

I mostly canabolised yours anyways! :) But yeh here you go. The webservice version returning AJAX from python can be found: - AJAX geohashing - Example using the web service

The implementation also has the ability to tell you whether the particular area is water, park/forest or other. It does this by checking the colour on google maps and doing a thresholded euclidian distance check against the expected colours for those things. Also If its water it tells you its probably not accessible I wanna try to add more features like this, things like rating locations based on food and letting you say how far your willing to travel

Thanks to User:Sigmund Fraud from the IRC channel for the space on his server with python installed - SinJax

I've added my own python implementation to the main page (only 5 lines) -- lilac

_very_ nice, im in awe! Though it must be said my concentration was usability as a web service and the implementation of that imaging stuff. Still. Very nice stuff. I love python :) - SinJax

Added a shell script implementation to the main page (slightly shorter than the Python version; let the flames begin) -- gnomon

deeply awesome; no flames from me -- lilac

${var:x:y} slicing isn't portable, so you should really call it a "bash script" and change the #!/bin/sh. I came up with nearly the same thing:

(echo 16i; echo -n "$(date +%F)-$(GET xrl.us/djiopen | col)" | md5 | sed 's/.\{16\}/0.&p/g' | tr a-f A-F) | dc

On Linux, it's md5sum, which prints a "-" for stdin, but dc happily eats that. Your web interface for getting the Dow data is much better/more flexible than that ganky little shortcut url to Y! Finance (they have historical data in .csv too, but at a different interface so I didn't include it), but consider using sed instead. You only have to fire up one dc at the end of the pipeline which is much cleaner IMO.

To make it print out my full co-ordinates, I created a graticule file:

echo -e '42\n-71' > graticule

and appended

| paste -d'\0' graticule -

to the pipeline. If you wanted it put it in a script file as you have and pass them as args, you could (untested):

| while read f; do echo $1$f; shift; done

I'll stop here before I get any farther offtopic :) --Decklin

Automatic land-water filter / other filters

geosplashing
Pyron Beta 12:42, 21 May 2008 (UTC)

Does anyone know of open-source data for determining whether a coordinate lies on land or water? This would be an interesting feature in a calculator which tries to automate this a bit so one does not have to manually check against a geohash calculator every day.

E.g:

• every morning, calculate the days geohash
• apply filters:
  • is coordinate on land?
  • is coordinate not in known list of bad regions (area 51, etc.)
  • other personal filters, e.g. is coordinate < n miles from home
• if pass all filters, notify of coordinate, provide image of (or link to) map

--Recursive 11:15, 21 May 2008 (UTC)

Hmm. Seems like http://www.openstreetmap.org/ found this data somewhere, so presumably it's only a matter of digging up that separate dataset and parsing it. Here's another mess of links: http://opensourcegis.org/

OSM has some form of land detection, but it's a little crude. The readme in [1] should provide the details required. -- Edgemaster

(of course, this isnt the exact data in the OSM database, but a highly simplified version) If you want to go to the trouble of parsing all of the coastline shapefiles, they're here: [2]

And a third edit to say that we use this datasource.

Of course, having the data is not necessary, merely being able to query a web service for whether a coordinate is land is sufficient. The crudest approach would be to graphically scrape google maps, but, that's kind of lame. --Recursive 11:24, 21 May 2008 (UTC)

So i'll assume by kinda lame you meant awesome and i went ahead and implemented that, here it is: Enjoy

Wouldn't it be simpler just to have a standardized method of determining where to go if the geohash is over water? Say, "Follow shortest straight north, east, south, or west line to land and meet at the coast" or something along those lines. -- Curtmack (67.141.84.48 01:44, 22 May 2008 (UTC))

But whats the point of simple when it ruins my fun. Also i think it'd be better to try to keep everyone meeting at the geohashes or as close to as possible. Then we'll get custers of people. More people means more fun :). check out the implementation of this here: [Finding Alternative Geohashes]

Hence the point of a standardized method. Although I agree, it is more fun to try and go over water, but it could be horrendously difficult and downright impossible in some cases (i.e. your geohash is several miles out on water and all you can conceivably rent is a rowboat). Just a thought anyway. Curtmack 00:26, 23 May 2008 (UTC)

Active Graticules

Can it be done to automatically sort the active graticule list? --Psud 11:49, 21 May 2008 (UTC)

be useful if people started catergorizing their pages too --Ryan the leach 12:34, 21 May 2008 (UTC)

What if we redo the active graticules entirely? Better soon than later. Create a "Active Graticules" page with lists of all graticules, and then only list the most active graticules on the main page? --Tsen 13:53, 21 May 2008 (UTC)

Agreed. There should be a page of ALL graticules and then once it has had more than 5 visits (or some other arbitrary number) it can be moved to the 'active graticules' list on the main page. --KDinCT 14:10, 21 May 2008 (UTC)

How can we add new Graticules? I live in South Africa and Geocaching itself is a becoming a big deal. Can we add an African region? More specifically a South Africa; and then Johannesburg?

Just edit the main page, copy/paste an existing entry, alter it to match your location and save. It should create a link to your page, which should still be blank. Then edit that, (perhaps copy/pasting another graticule's page to keep a semblance of order) and add all you want.

On another note, I'd be willing to reorder the pages for Active Graticules and cut down the bulk, but what criteria should we use for "More" active graticules? Since this has only really hit the interwebs in the last day, there hasn't been time to see which areas are really going to be busiest. Do we create an active graticule page now, removing them all from the front page and then adding more active/interesting ones to the main page as they come up? --Tsen 03:25, 22 May 2008 (UTC)

What about just having categories for "at least 10 users", "at least 50 users", "at least 100 users", "at least 500 users", "at least 1000 users" etc. There seems to be a convention developing of listing user names in each graticule for those who are interested in participating (though this probably doesn't scale well... perhaps an average count of recent Saturday participants instead?). Then as time goes by and they grow, we can just start linking to bigger and bigger category pages to see the most active groups. --Cahlroisse 05:44, 22 May 2008 (UTC)

I would suggest that, after this weekend, a graticule is only listed as active if a meeting has taken place. That is, it has been proven that at least two strangers have actually met on a weekend by geohashing in the graticule.--121.73.94.250 05:55, 24 May 2008 (UTC)

Small Islands / Countries

One problem with this are small countries such as Malta ([3]). It's split into two reagions and both are very small relative to the degree grid box. It would make more sense two have the entire country as part of a single region (i.e. shift by half a degree). This of course would not occur to you, big country - americanites ;)

I don't see why this would be a problem since if it is a point on the western part of the grid then you go to the east side of the island (and it's associated degree grid box) and if it is a point on the eastern part of the grid then you go to the west side of the island (and it's associated degree grid box). But then again I am just a big country Americanite.

We could, for such case, agree to add .5 degrees to the coordinates as needed to have the meeting point on land, or you could just all agree to swim or row to the meeting point instead. - Sparky

Yeah, in Halifax NS (where I live), most of the square is in the sea. In Victoria BC, (when I happen to be right now), a good chunk of the square is in the sea, and a good chunk is in another country. In Wellington NZ (where I'm from), most of the square is either in the sea or an expensive 3-hour ferry ride away on another island. I suggest that you should be able to set the centre of the square with a higher granularity - say 1/10 of the square size. Then it's still not too hard to make sure everybody is using the same square, and it allows you to position the square such that it's mostly overland, and mostly in your country. 24.68.238.83 14:06, 21 May 2008 (UTC)

I've said this before, and I'll say it again: the boundaries of the cells are completely irrelevant, because the meeting point is in the same place in every single cell. The meeting points are exactly 111km apart in both directions, and there will be a meeting point within ~78km of every single point on the surface of this planet. If that point happens to be 30km out to sea, there will be another one 111 - 30 = 81km inland. If you live on an island which is significantly smaller than 111 * 111 km, well, you're just not destined to meet people, I guess ;-)

Okay. Don't get me wrong. I agree with the system, but what you're saying isn't entirely correct. It is possible to have meetup points further apart than that. Like, for example, what if you lived in Haywards Heath, UK. It's close to the Prime Meridian. Because of the algorithm, it's possible for the geohash to give something like .99999 west or east. Like for example May 11. It's just a hair over that, but it's possible to get further. (Greenwich may 18th...). McKay 15:21, 21 May 2008 (UTC)

Yes, you are entirely correct. I didn't realise that the algorithm mirrors the coordinates around the 0 medians (on the north-south and east-west boundaries). This artifact of the algorithm can be removed by inverting the fractions in, for example, the east and south hemispheres. - Sparky

Zero degrees longitude

Note that there is a negative zero, for those of us near the Prime Meridian (e.g.: London). The algorithm will then lead to longitudinal coordinates such as -0.1234 instead of 0.1234.

Correct - this is by design. Zigdon 14:55, 21 May 2008 (UTC)

Heh, indeed - To clarify, I added this info because London West was originally listed as longitude -1 (as opposed to -0). I didn't intend to imply it was a problem to have negative zero, I just wanted to flag the issue. Sorry for any confusion. 194.74.151.201 16:19, 21 May 2008 (UTC)

Actually, it appears zones are numbered with the WESTMOST longitude coordinate. In the west, it doesn't make much intuitive sense, because, for example, all locations in a zone labeled with -80 longitude begin with W 79°. As such, London West actually is -1. Tjtrumpet2323 22:21, 21 May 2008 (UTC)

A heads-up to the person who created the rss feed: the script doesn't recognise the existence of -0, but if you pass it -1, you get (as you shoulld) a longitudinal co-ordinate -2 < x < -1. There's no way to get any of the graticules where -1 < x < 0.

If this was by design, then can the design please be reconsidered? For everyone else, the maximum distance to a meetup is the diagonal length of a graticule, but for people on zero degrees longitude / latitude, it's further than that. For instance, the nearest two meeting points to me (in Cambridge UK, at 52, 0) are at 52.179467°, 0.861536° and 52.179467°, -0.861537°, both of which are too far for me to visit. Can we change the algorithm to round down, rather than truncate, the starting location? -- lilac

The map tag for the graticule template also doesn't recognise -0 - for example, it is impossible to add a map to Northampton, United_Kingdom, the map just keeps centring on Cambridge. Nicktaylor 14:12, 23 May 2008 (UTC)

This will be fixed shortly - you will able to specify the 'abs=1' tag, which would mean that entering "-1" would be the grat between -1 and 0 (instead of -1 and -2). Zigdon 17:43, 23 May 2008 (UTC)

Am I to understand that with the new parameter, one will be able to directly specify the integral portions of their home coords? That would be ideal. In any case, please make sure that the reflections around 0 (both E/W and N/S) end up being very well documented when you make this change. At times, the Active Graticules page has been a mish-mash of many systems. --Tim P 22:16, 23 May 2008 (UTC)

I created the -0 Issue to summup this problem (and to bring a solution).

Page Forwarding

I am just learning how to work on wiki's so please forgive me but I am wondering if there is a way to make a page automatically forward to the correct graticule page based solely on the latitude and longitude. For example, if I am linking to the page currently called "Springfield, Massachusetts" I want to link to 42, -72. I see this as a benefit in case someone later down the street decides to rename this page "Springfield, MA" and my "Springfield, Massachusetts" link no longer works. Or are the links not changed when the page name is change?--KDinCT 17:17, 21 May 2008 (UTC)

There are some ways for this.

-Having pages redirect to others, using #REDIRECT [[NewPagename]]

-You can give links different names using [[Pagename|Linktitle]]

This should get you running. Nazgjunk 17:30, 21 May 2008 (UTC)

bug in reference implementation

The reference implementation is biased against results in the .0..., .0... range. This seems to be because the code that converts a hash string to a fraction stops dividing as soon as the remaining characters are all false (zeros.) This division should probably happen a fixed number of times, instead. 76.121.107.210 17:26, 21 May 2008 (UTC)

Good catch, fixed Zigdon 18:18, 21 May 2008 (UTC)

Great! I also noticed another issue with the perl script -- the page you're retrieving the DJIA value from does not currently have the value for today, so the script is accidentally using the value for yesterday instead. this page is not currently showing a value for 5/21, which the script expects to be there. 76.121.107.210 20:04, 21 May 2008 (UTC)

True - the cron job on the server doesn't get the data from that page, so it's not an issue there. For the sample.pl, perhaps I'll edit it to use a different page if you're trying to load the coords for today. -- Zig. 159.153.4.51 05:15, 22 May 2008 (UTC)

The comic is also a bit vague about exactly how the hex value is converted to a decimal value. One would assume from the description that the hex value is simply converted straight to decimal (FF -> 255) and then appended to the lat/lon coordinates; the reference implementation, however, shows that the hex number is instead converted as a decimal fraction (0.FF -> 0.99609375). This latter approach inherits all of the accuracy problems inherent in converting between decimal and hex/binary fractions. Can't do much about that now except whine, I guess. Ooh, and a cheese platter? Mine's the chunk of reggiano parmesan, thanks. -- gnomon

Yes, the comic states you take the hex as a fraction. Not 'abcdef' but '0.abcdef'. What accuracy problems? you can describe any number between 0 and 1 to the nearest 1/2**16. That translates to about 5 feet or so? Or am I missing something? Zigdon 23:54, 22 May 2008 (UTC)

Actually, that would be 1/(16^16) for 16 fractional hex digits, which translates to something on a microscopic scale. --Tim P 22:18, 23 May 2008 (UTC)

"I'm sorry, our measurements show you missed the meetup by one ten-thousandth of an angstrom."

"Only because I was moved when you measured me!"

--Xkcd 16:36, 24 May 2008 (UTC)

Negative coordinates and adding versus appending

There's possibility for confusion with regard to graticule coordinates. For example, the larger NYC graticule's longitude ranges from -73 to -74. If, like it seems in the comic, you're supposed to append the random <1 number to the coordinate, then NYC's graticule should be listed as 40, -73 (since every point within the graticule has longitude -73.xxxxx). If, however, you're supposed to add the random <1 number to the graticule, then NYC's graticule should be listed as 40, -74 (since the random number is always positive, this will always lead to a -73.xxxxxx number unless the random number is zero). I therefore recommend changing the algorithm to specify adding the random number, not appending it.

As a side note, the implementation of the algorithm linked to from the comic reflects this confusion. If the link includes zoom parameters, it gives the coordinates of the NYC graticule as 40, -74: http://irc.peeron.com/xkcd/map/map.html?lat=40&long=-74&zoom=8&abs=1 However, if the link does not include zoom parameters, the longitude has to be changed to -73 to give the same graticule: http://irc.peeron.com/xkcd/map/map.html?lat=40&long=-73

The map always marks the northwestern edge of the graticule - otherwise, it'd have to add a parameter for N/S and E/W. So when given the 'abs' argument, it takes your coordinates as the northwestern corner, and without it they're parsed as what the comic presents them as. Perhaps this should be made more explicit though. Zigdon 18:22, 21 May 2008 (UTC)

failsafe distributed geohashing

There are a few undesirable issues with the data source for geohashing:

1. It relies on data from the stock market, and the stock market is a yucky, yucky institution.
2. in case of a nuclear winter, terrorist attack, natural disaster or other breakdown of society, the data source for entropy disappears (same with weekends or mornings before 9am).
3. it is insufficiently DIY.
4. there is only one location per day (or three days in the case of weekends). This means that if you discover that your communication channel has been compromised and that THE ENEMY knows where you are going to meet, there is no way to broadcast new information over the compromised communication channel such that the BAD PEOPLE won't be able to find out the new meetup location but the GOOD PEOPLE will.

A solution: The weather is a source of data that is always available. Further within a local area weather is fairly (though not completely) constant so it is suitable for DIY weather stations. If time is built into the procedure then it can give multiple points per day, plus a broadcastable variable such that the BAD GUYS can't figure out the new location (assuming they don't know how you generate the locations).

Procedure: Choose the date plus a begin and end time (measured in 10 minute blocks). Then you go and find out weather data for yesterday for your location. From this choose the data points for you start and end time as well as the max and min temp (and when they happened. Then use the following (or something like it) to generate the data for the hash:

• <date>
• <start time> <last digit of temp (decimal point rounded)> <second and third last digits of pressure (last digit rounded)>
• <end time> <last digit of temp (decimal point rounded)> <second and third last digits of pressure (last digit rounded)>
• <last digit of max daily temp (decimal point rounded)> <last digit of min daily temp (decimal point rounded)>

Example: [23-05-08] [6.50 9 02] [7.00 9 02] [0 2 4 5] (square brackets are only to enhance readability). from original values:

• date: 23-05-08,
• time: 6.50-7.00 (24 hour time of course),
• temp and pressure at 6.50: 18.6 C 1018 hPa,
• temp and pressure at 7.00: 18.9 C 1017 hPa,
• max temp:29.9 °C at 12:25,
• min temp:13.5 °C at 06:52.

Because such a small time window was used the temp and pressure ended up being the same for our purposes, however for time windows of an hour or longer this would rarely be the case. If you want more entropy you could add sunrise/setplus, average rainfall over the preceding month, max and min UV index, etc. Importantly, it should use variables that will be different from one day to the next, but which are able to be measured with reasonable accuracy from any place in a smallish city. This means that the fine end of a measurement (ie. decimal point) should not be used, nor should the gross end (eg. the thousands for hPa and the tens for temp). For those without their own weather station you can easily use one of the billions of publicly available ones eg. http://www.wxqa.com/stations.html .

-rjs.

I don't see this as failsafe. You all have to agree on a particular weather station. If everyone had their own weather station, everyone would get slightly different readings. Even minor differences can have major effects on the resulting md5 calculated location. --engunneer

Besides, what's to say that your chosen weather station will be failsafe itself? --Tim P 19:07, 23 May 2008 (UTC)

Also sunrise and sunset are not entropic at all; there are algorithms in place to calculate this data very far in advance. --Tim P 19:08, 23 May 2008 (UTC)

Larger Events

If this turns out to be successful, I think it would be nice to group sets of graticules together and have state- or even national-based events (although this may be tricky in nations that cross timezones... maybe we could just have time-zone based events) for special occasions. StJimmy

How are you going to do that when you have no idea where you'll be going or even if it's public property? Gormster 15:38, 23 May 2008 (UTC)

Who owns the land?

One of the things that early geocachers quickly learned is that even public land that they thought would be safe to hide a geocache on ("...it's not harming anyone...") was "owned" or cared for by someone. I think geohashing is going to quickly run into a similar problem. You will get your coordinates, everyone will rush out there and maybe you'll even find a public right of way that leads you close. But the times someone ends up on private property chasing their GPS signal or people go off-trail in a public park against posted policies or whatever slight someone takes like if they land in a graveyard and some participants still want to play "games" upon arrival, well, those are the ones that geohashing will be remembered for and the people who follow out there that day are not going to have any idea what kind of hurt feelings or possible repercussions they're about to run into when they arrive.

Just a caveat from a learned geocacher for geohashers to keep in consideration. No means no and even the times when you think you're in the right, you might be doing more harm than good by forcing the issue. Be smart from the time you leave the house to the time you determine you have no right to go any further. 24.218.222.86 01:59, 22 May 2008 (UTC)

I agree with this, to some extent. The point of this idea is adventure, so we sort of want to have weird places to try to get to. But sadly we can't just walk anywhere we want, so some filtering of the locations might be in order. "bad" locations that end up on private land or non-walkable locations might get moved to the nearest accessible point or recalculated with some predictable randomness added to the hash until an acceptable solution is found. This would probably be hard to implement correctly though, and it could be that a super simple solution is best. - forest

You're not thinking globally. No one can pick a proper new location every day for every place in the world. Yes, some days the locations in your area might not work out, that's too bad. Try again tomorrow! Zigdon 06:43, 22 May 2008 (UTC)

Think more pragmatically: How early in the process can you determine that the day's location will "work out"? Is there a way to learn from others' experiences for the day that the site didn't "work out"? What is the impact on the person who owns the land where the hash isn't "working out" when people will just continue to show up unannounced? How can the geohashing/xkcd community avoid a bad rap for following a "wierd internet trend" that leads people to just showing up en masse on a stranger's front yard/street corner/field? Those are a lot of the same questions that geocaching (particularly non-Geocaching(tm) geocaching) has had to deal with. Geocaching(tm) avoids some of this by requiring approval for locations and methods of hiding before being listed for the world to see. Here, the hash is determinable without any central authority or QA. This means there's little control over the actions of the community members...which could mean problems for the community and the activity as a whole that should be given some consideration.

My answer would begin with laying out some guidelines in a high profile place, like this wiki's Main Page, to help shape how new community members may be influenced. Some things may be obvious to certain people who come here to "just have fun" or "go back another day" but you'll find someone who will want to do something like a "10 days in a row Achievement". There will be community members with less self-control who will want to run through someone's property just to "catch'em all" or keep up their streak or whatever have you. Again, these are just some of the issues I have seen in geocaching which may even be more exacerbated by the fact that you don't even need to search or leave something behind to geohash, therefore you're more likely to see less harm from trying to reach your coordinates when they're not legally accessible. I haven't even gotten to the warped problems, like having a group of 4-5 people meeting up in the bushes at a public park, just to get reported because they're less than 30 feet from a group of children playing in a sandbox. Then there's the xkcd twist in that situation...half of the hashers are wearing raptor masks and the other half have swords. 24.218.222.86 18:00, 22 May 2008 (UTC)

I got distracted from your point by your awesome idea at the end... =-)

Um, back to your point. You're right, geohashing has nothing to protect. Geocaching wants to preserve the ability to place things and the expectation of finding them again. Geohashing wants to preserve people showing up randomly. The only way to screw that up is to overregulate it. Not to say we won't individually want to minimise hassles with less lateral thinkers, but don't we deal with that daily?

I think the allure is doing something orthogonal to "normal," and "approved" is a directly conflicting goal.

Now, we like figuring out systems, so you could probably with some success cast a best practices guidelines section as a parameterisation of what property owners/police want to perceive. Taking that idea too far, we could have a cover story where we're all in a book club or something else that can be ignored as "safe." (Everybody arm himself with a copy of A Wrinkle in Time.) On a side note, unless you know some librarians, you might be surprised the things a lot of them do on weekends. —Christian Campbell 18:19, 23 May 2008 (UTC)

How close do you have to get to have achieved a location? The location for me today is ending up in the middle of a field of wheat. Would the nearest field boundary be acceptable? Or the nearest public access point?

Many States and Counties have an online GIS system that allows you to lookup more than just an areal photo of the land, like who owns it, for example. I suggest people look into this before heading for a location to make a more informed decision about whether and how far to proceed. Example in Charlotte, North_Carolina . WokTiny 22:56, 23 May 2008 (UTC)

FRS Radio Frequency Standard

How about coming up with a frequency standard that we can use with two-way radios? Then anyone in the vicinity can announce their arrival and meet with the others nearby. --waq

Agreed. This way, nobody should feel the need that they have to trespass. Obviously, in any case, you'll still have people who will try, but at least you can mitigate the possibility.

Only potential problem is for the non-Saturdays, who's to say when anyone will show up? 16:00 local time is only the standard for Saturdays. On a Monday, someone could go at 12:00, announce his (near) arrival via radio, and no one would answer. That wouldn't stop anyone from trespassing alone at 20:00. --Tim P 19:17, 23 May 2008 (UTC)

BTW, I suggest FRS Channel 6, if for no other reason than the comic number ends in '6'. --Tim P 19:19, 23 May 2008 (UTC)

Agreed. I formally propose that FRS Channel 6 (US) and PMR446 Channel 6 (Europe) be made the official xkcd geohashing radio communication standards. Waq 12:26, 24 May 2008 (UTC)

Split Cities

I have created a Split Cities category (temporarily?) for cities such as Chicago and Washington, DC, which don't quite fit squarely into a graticule. It's just a way to categorize them, not a proposed solution to the problem (hell, it's even debatable whether there is a problem). Feedback? Tyler 02:05, 22 May 2008 (UTC)

I think the alternative i've coded up should solve this problem as well. Check it out: Alternative Geohash

In the event of a split city, I think the simplest solution is for people to go to the nearest location. If you live in the north half of a split city, and the point of the day is far north, just try the point in the graticule directly south, where the point is probably within the south urban area of your city. no? WokTiny 15:46, 22 May 2008 (UTC)

No city can possible have it worse that Columbus, Ohio: split into four exactly in the center. Tytrain 01:04, 23 May 2008 (UTC)

In Sydney we've solved this problem by making it officially whichever one is closest to the CBD. If there's any contention, it's xkcd rules - whoever posted first is correct. Gormster 15:35, 23 May 2008 (UTC)

Achievements

I made an Achievements page to list some extra challenges that can be achieved so people can brag about some of the harder places they've gotten to (eg, i've got a Water GeoHash achievement when me and a friend hired a boat and went to the location on water). I thought of a few, but needless to say there are quite a few possibilities. zorg

Facebook

It was inevitable, because I am a Facebook whore: Geohashing on Facebook I might start work on an app after I finish my current one. Gormster 12:51, 22 May 2008 (UTC)

There are also some local groups. So far, I know of: Geohash - Toronto, IVSLO Geohashers (Southern Cal somewhere?), and Geohash - Denver (which I created, for the record). --Doubt 21:00, 22 May 2008 (UTC)

I've also created Oklahoma City Geohashers. Trvsdrlng 19:51, 24 May 2008 (UTC)

Automatic GPX File Generator

I have modified the sample perl implementation so that it automatically generates a .gpx file which you can upload to your favourite GPS device/software. Download here: [4] Before you use the script, you need to modify it and put your own lat/lon values into the corresponding variables at the beginning. ~~Wansti

Use of one degree grid sucks

The usage of integer lat/long as the grid for this is really simple but it doesn't perform well. For example, the DC metro area is split into four zones each which contain a small populated area and a large area no one wants to travel to. Alternatively, consider Milwaukee Wi, where there is a 80% chance of the meeting location being in the middle of Lake Michigan, likewise for a number of other coastal cities.

Instead what should be done is someone should search for a tessellation of the world where each tile has the same area as a 1deg/1deg grid but optimized on the following criteria:

• Tiles should not span national borders.
• Where the boundary lines avoid areas of large population
• Tiles should not simultaneously contain large amount of water and non-trivial numbers of people
• Any others?

Once a tessellation is found the hashing could just be an index into each tile. It would be somewhat more complex, and require knowing the tessellation, but it's not like anyone is doing MD5 in their heads.

Perhaps a contest could be held for tessilations? People could compute ones then argue why theirs were the best. ;) --Gmaxwell 22:01, 22 May 2008 (UTC)

People don't want to travel there? I wouldn't be quite so sure about that. Geocaching is rather popular in large foresty areas, and the visited hashes we've seen so far were busy enough even though they were in the middle of nowhere. I actually see your point, but I think that it's not possible to create anything better than this which isn't particularly difficult or annoying to implement. As for the national borders - I'm fairly happy that's not too much of an issue here in Europe ;) Nazgjunk 22:07, 22 May 2008 (UTC)

At least you can expect find something at a geocache. Seems to me that the value of a geohash is meeting the other hashers. When the selected location is often multi-hour drive (due to geographic features and lacking roads) into an unpopulated area it's likely that no one will show. So people will lose interest and be aware of it the few times it is in a good location. With something around 300 geocaches found I think I've only run into other geocachers three or four times or so, and most geocaches are in locations far less random than geohash locations.

I think the people who will spend hours getting to an adverse location will really enjoy the conversations they'll have on the days when they do run into someone. And I think you may be underestimating just how geeky xkcd readers may be -- to me the adverse locations sound most attractive. For those who'll go only when "it is in a good location," there's still the joy of the hangfire of not knowing when that will be until just beforehand. I like the idea of multiple people having determined in their heads to partake in an adventure of unknown complexity, even subject to whatever personal qualifications, where the fruit of the mutual determination doesn't materialise until the adverturers converge on the target. Lastly, I guess geocaching doesn't have any goal of meeting others, and wallclock time is not part of the target, so it doesn't sound surprising you'd rarely run into others? —Christian Campbell 17:27, 23 May 2008 (UTC)

Even when crossing borders is easy, differences in available data might lead to different tessellation rules. I know where to get good population data for the US, but I don't personally know how to get the same data for Mexico.  :)

As far as complexity goes.. geohashing already requires an MD5 .. is indexing into a big table of polygons that much harder?  :) (though the MD5 should be dropped.. if the random seed is random enough, just xoring the digits should be more than random enough...) --Gmaxwell 22:24, 22 May 2008 (UTC)

No one claims the DJIA is very random. But with the MD5, even the slightest change produces a completely new point. That's why I'd argue the MD5 should never be dropped. Zigdon 23:57, 22 May 2008 (UTC)

In Europe, meeting with people from other countries only makes it more fun. Integer grids are good, you can always go to another graticule if it's closer. Nobody says you should take your home's location, you can travel to another location and take the geohash there. --FrederikVds 13:56, 23 May 2008 (UTC)

You're missing the point. See Lowman's post below. Gormster 15:33, 23 May 2008 (UTC)

I don't think so. Maybe you understood me wrong. What part of the point am I missing? --FrederikVds 17:33, 23 May 2008 (UTC)

iPhone Implementation

Last night I finished a rough implementation of this to the iPhone 2.0 Beta SDK. Right now it uses your current location and date and then does the math, then gives you a map with the destination address along with directions to there from where you are at. This will be even more useful if the next 3G iPhone come with GPS, until then it uses it's less accurate cellular and wifi location tools to locate you. I plan on adding a way to select your date and your desired graticule as well. Eventually I'll also investigate filtering of the results in watery areas. I can't distribute it currently, but as soon as I can I'll make it available. -- Shakedown

Should be moved to iPhone

Saturday's meetingpoint

I was wondering. Is the saturdaymeetingpoint calculated with the date of saturday and the dow opening of friday? Or is the date you use always the date of the dow opening? --Evo-- 13:22, 23 May 2008 (UTC)

My understanding is that you hash in Saturday's date, so that the locations for Fri, Sat & Sun are all different, and are available at 09:30 EDT on Friday. Speaking of which, could someone post the Saturday location? I don't have a hasher. AshleyMorton 13:40, 23 May 2008 (UTC)

Yes, that's right... Current date, most recent DOW opening. Speaking of the hasher/locator, is anyone else having trouble with the peeron one? everytime I hit update it jumps the point around a couple times. I'm at a loss for where I'm supposed to go. --WokTiny 14:06, 23 May 2008 (UTC)

For some reason it adds a few zeros to the Dow Jones every time you click calculate, screwing up the algorithm. StJimmy 14:22, 23 May 2008 (UTC)

I'm not seeing this. Steps to reproduce the problem, or is it fixed? --Xkcd 16:40, 23 May 2008 (UTC)Xkcd

I'm still seeing this. Just go to the page in Internet Explorer and either move the map, zoom, or hit the "Update" button again. The coordinates and the marker will change. The bug doesn't show up in Firefox but it does in IE7, I don't know about other versions of IE.--Ahecht 18:37, 23 May 2008 (UTC)

Atom Feed

I noticed yesterday that before the stock exchange data becomes available, the atom feed creates a kind of 'intemediary' geohash using todays date and yesterday's data. This might be intentional, but personally I find that undesirable on weekdays. Could it be modified to show yesterday's date and geohash until data is available? Nicktaylor 14:04, 23 May 2008 (UTC)

I'm currently working on getting an alternative Atom Feed implementation ready for public use (although I think I'm going to wait until the Time Zone issue is resolved). Mine will only update at 09:40 Eastern daily (accounting for DST changes), and uses the irc.peeron.com source for the DJIA, which is updated at 09:35.

I will certainly post it here when it's done, so stay tuned. --Tim P 20:10, 23 May 2008 (UTC)

The time zone issue has been resolved with the 30W Time Zone Rule. I'll continue to work on getting my implementation ready. --Tim P 04:34, 24 May 2008 (UTC)

Error on page?

Just zooming in and out today gives me random meet up locations, any one else having this issue?

Yes, I am experiencing this as well.

It seems to change everytime the applet is reloaded (refreshed, updated, zoomed, or moved) Is there any one who can fix this?

I'm not seeing this? What browsers are you using? Zigdon 17:48, 23 May 2008 (UTC)

I'm experiencing this problem on IE6. MOE37x3 18:10, 23 May 2008 (UTC)

I get the error in IE7 but not Firefox.--Ahecht 18:57, 23 May 2008 (UTC)

Same here, except I us IE6, not 7. Firefox fixed my woes, though. - MythGuy

I, too, am experiencing this. I used the the alternative locater though. http://geohashing.electronicwar.net/

I hope we can we can get this fixed soon. - MythGuy

With the debugger on, I noticed that "00" is appended to the DOW opening every time I click "Update." This changes the hash each time, creating random locations. Zigdon, we need your help. 16:33, 23 May 2008 (UTC)(James)

Ah. Well this is creating problems for me. I used the alternate locator, got location A, went to my local page to see if others might be planning on coming, saw a different GPS (thus giving me location B), I went to the real map and found that the first location that it pops up with is always the same, so I have three locations now... What do I do? - MythGuy

Gah. Ok, I can reproduce this in IE6. I'll see if I can find some simple hack, but doing browser specific code is evil. Zigdon 21:36, 23 May 2008 (UTC)

Ok, it should be fixed in the (beta) version: http://irc.peeron.com/xkcd/map/map2.html. This will become live once the 30W decision is final. Zigdon 21:47, 23 May 2008 (UTC)

Flags

Did you ever watch The Amazing Race? They had red and yellow flags and arrows to signify that there was something to do with the race nearby. Red and yellow were their colours. I'd suggest a similar two-colour pairing so that fellow geohashers can easily find each other at the marker. I'm gonna suggest blue and green, because, you know, geo. Gormster 15:43, 23 May 2008 (UTC)

Except that blue and green would blend in with the scenery? --WokTiny 15:47, 23 May 2008

Won't be liking that choice (i.e. blue and green) during the hunting season on a MNIMB Geohash. --KDinCT 16:12, 23 May 2008 (UTC)

 ??? I'm confused. Gormster 00:29, 24 May 2008 (UTC)

How about brown and khaki -- and antler hats? --Ahecht 16:56, 23 May 2008 (UTC)

Um, who would be cleaning up all these flags from all over the world? I don't think we want to be littering quite that much? Zigdon 17:48, 23 May 2008 (UTC)

If you need flags for anything, they make a biodegradable flagging tape for just this sort of reason. Geocaching sometimes uses it to signify things during day-long events. If it gets left behind it's no big deal that way. 155.41.240.238 18:55, 23 May 2008 (UTC)

Okay, when I said flags I didn't mean literally flags. I meant something to alert others to your presence. It can be anything, paint, tape, as long as it's those two colours. Gormster 00:29, 24 May 2008 (UTC)

World map

The Active Graticules page is getting too big, so I was thinking about making a world map, linking to the graticule pages. I'm trying though I don't know if it's easy.--FrederikVds 16:03, 23 May 2008 (UTC)

Amen to the Active Graticules page getting too big. I too was trying to think if there was a visual way to lay it all out. Or a way to break it up so it isn't such a huge list. But then again if all of the graticule pages are properly categorized with countries (and states) the category page will help locating graticules much easier. I will be interested to see what you come up with. --KDinCT 16:10, 23 May 2008 (UTC)

The code will probably be something like Template:Worldmap, only the wiki doesn't seem to let me use <script> tags for obvious reasons. I was also thinking about using an iframe, but it doesn't let me use that either. How is it done for the <map> tag? --FrederikVds 16:36, 23 May 2008 (UTC)

The <map> tag is an extension I wrote to the wiki. Would a link from the map tool itself to the appropriate wiki page be useful? Zigdon 17:49, 23 May 2008 (UTC)

I'm not sure what you mean. My basic idea was a big world map (Google Maps) with all active graticules surrounded by a red rectangle, and clickable. Maybe you can extend your map tag to do that?

Edit: I tried if it's possible using a static map image and a table, but that's too hard. --FrederikVds 19:10, 23 May 2008 (UTC)

The new version of the map page (which should go online tonight) includes links to active graticules. It doesn't make it obvious where they exist - I'll see if I can generate a gmaps overlay to make browsing easy. Zigdon 03:01, 24 May 2008 (UTC)

Missing Historical Data

There is a good chance that no one cares, but the reference Geohashing Coordinate Calculator will not work for several valid dates. I think some just havent been copied from the previous day, but some may have just been missed. I've put a list of those dates up, delete it if you'd like. --ZorMonkey 14:20, 24 May 2008 (UTC)

Maps and pre-30W coordinates

I don't suppose its possible for me to get the map tag on 2008-05-21_54_-2 to show the coordinates as they were when the trip was made, ie, under the original rules? Nicktaylor 18:14, 24 May 2008 (UTC)

Not presently. I'm surprised Randall didn't write a split-date into his implementation. --Tim P 20:09, 24 May 2008 (UTC)

Update: I've updated Template:30w compliant to allow for implementations to be flagged as partially compliant. I've also updated the Implementations page accordingly to show that the official interactive calculator (which is used by Template:meetup graticule) falls into this category. Hopefully all will be resolved soon. --Tim P 20:25, 24 May 2008 (UTC)

New award?

So, I discovered I can see the point from my backyard. Is there an award for that? 2008-05-24 40 -111 McKay 18:27, 24 May 2008 (UTC)

How to recognize each other?

There should be some distinctive sign for geohashers so they can distinguish fellow geohashers from people that are just passing by. The problem is, if you just start asking random people "are you geohashing?" you are going to make a fool of yourself, but on the other hand, if you spend an hour standing without moving in a weird place looking particularly weird, you are also quite likely to make a fool of yourself. So this sign should be obvious enough so that geohashers would immediately recognize it, but at the same time discrete enough so as not to draw attention of other people. --Ilia 20:30, 24 May 2008 (UTC)