Talk:Main Page

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• Use Template:Graticule to generate a map of the graticule for graticule pages.
• Use Template:Meetup graticule to generate a map of a day's location for meetup/expedition pages.

• All scripts and implementations written for the Geohashing algorithm should be posted at Implementations. Any discussion on an implementation's bugs should be directed to Talk:Implementations.

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 the 'abs' parameter, it gives the coordinates of the NYC graticule as 40, -74: http://irc.peeron.com/xkcd/map/map.html?lat=40&long=-74&abs=1 However, if the link does not include 'abs' parameter, 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)

This absolutely needs to be made more explicit. --Tim P 23:44, 24 May 2008 (UTC)

Most of graticules are already referered using the -0 convention (except few ones in United Kingdom). Again, the whole problem has been sum-up (including reference implementation change) in page -0 Issue. And yes, it should be made explicit. --Gissehel 13:54, 25 May 2008 (UTC)

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)

Agreed - If you have "Privacy Codes" on your FRS radio, I further propose using Code #1. Also, as a ham radio operator, I also propose 146.520 (the 2m calling frequency) --Scottkuma 19:14, 30 May 2008 (UTC)

I would advise against using Privacy Codes, as not everyone can use them... so those who have them should just use Code 0. --Tim P 19:40, 30 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

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)

I think that gets the Superbly Lazy Couch Potato Achievement. Darcy 01:56, 26 May 2008 (UTC)

I shouldn't think so. Just because he can see the spot from his backyard doesn't mean it's in his backyard. --Tim P 03:50, 26 May 2008 (UTC)

hahaha thats just unlucky really, so close but so far. --Zorg 04:03, 26 May 2008 (UTC)

How many points can you reach (in different graticules) in one day? Would require some luck, but it would be an awesome achievement / high score page. Or a different variation- choose a time frame (say a week 1 year ago) and visit all of the points from that time frame in as short a time period as possible. Thoughts? 70.162.29.88 22:58, 24 May 2008 (UTC)

Since there's a Twister achievement, don't you think there should be a tape measure achievement too? thepiguy

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)

I have added the Cincinnati Area Geohashers group. Scottkuma 19:34, 30 May 2008 (UTC)

I created a group for Lubbock Geohashers. elxverde 01:03, 31 May 2008 (UTC)

Google Earth app

It would be interesting if we could somehow tie these pictures that people are uploading in with the google earth program- an app that lets you select a graticule, get a list / visual of points that have been geohashed, and retrieve pictures specific to those points. 70.162.29.88 20:14, 25 May 2008 (UTC)

I'm already generating a KML file that can be used in google earth (and maps) to look at active graticules. If there was a page listing all the images and where they should be placed, it would be trivial to include those images there as well. Zigdon 23:28, 25 May 2008 (UTC)

Since all of the pages for specific meetups have the same URL format, they could just be scraped off of the meetup pages- if the meetup page has that image on it, it gets listed for that location. There's probably an easier solution though...

Complete list of historical locations

Surely someone has by now generated a complete list of the decimal parts of the coordinates produced by the historical data? It can't just be me wanting to see it, can it? Does anyone have a link to one if so? Even better if it was available as a map overlay...

I put up a set of Historical Location Data that I generated a couple days ago. It seemed slightly too ginormous to put on the wiki in it's raw form, but if anywone wants to, be my guest. Unfortunately there are some bad dates in there due to Dow data that was missing, but I'll get them updated. My hope was to use the data to generate a map overlay or allow you to click a location on the map and have it show you all the dates that a geohash landed in the vicinity, but my web programming skills are nonexistent. I could write a Windows app, but that's not so great for anyone. Someone else tackle it. :) --ZorMonkey 11:57, 27 May 2008 (UTC)

I also have a set of location data 1970 to present for W30 and non-W30. No bad dates that I know of, generated using the Perl implementation today. I lack the google-fu to plot it on google maps, but am happy to provide it to anyone. Data is comma separated. And since I've got a domain name sitting around doing nothing, Ill put it to use: here 'tis free for any use --Psud 12:29, 27 May 2008 (UTC)

I've updated my non-W30 data, and added W30 data. Our numbers are pretty close, so that's good! 14,000 units tests passed! :) It looks like you're missing a few dates though - for example 2008-03-28. BTW - Mine is also in CSV format, and includes the DJIA so it can be used to calculate the numbers if anyone else is playing with the algorithm. --ZorMonkey 03:19, 28 May 2008 (UTC)

My data is now hole-less (Pls let me know if you find otherwise), and complete back to 1928-10-01 in both W30 and non-W30! download here! <-- Note also now in format date,DJIA,lat,long

Also now the data is available bzipped or text. My intention is to keep it up to date - updating at 03:00 my local time (GMT+10). Let's see if my scripting is up to it. NOTE: New web page

Wow, nice! With that I regenerated my Google Earth KML file for Milwaukee. It now includes different color markers for different days of the week, and each marker has it's date associated with it so you can use Google Earth's (frustratingly tiny) timeline to constrain the dates you want to show. I wish I had to good way to create a webpage that would generate a KML file for any region you wanted... Maybe I can attempt that this weekend - but probably not. :) --ZorMonkey 04:28, 29 May 2008 (UTC)

Once you have one of the data files, it's pretty easy to generate a KML file for Google Earth. Google Earth freaks out a little bit, but it works! Here is a sample KML file (zipped) that I generated for the 4 graticules near the Milwaukee area, and the Python code I used follows. I've just started learning Python, so forgive any hackityness. In this state it needs to be manually tweaked to generate other graticule information, but it's pretty easy. Anyone know if it's possible to specify the marker color? --ZorMonkey 04:27, 28 May 2008 (UTC)

Instead of putting it here, I've put my increasingly terrible Python KML generating code up on the web. I'll update that file as I make changes and make it more (or less) awesome. --ZorMonkey 04:28, 29 May 2008 (UTC)

I have generated KMZs for the Cincinnati, Ohio and Detroit, Michigan graticules. Each are linked to off of the respective graticule pages. Scottkuma 19:35, 30 May 2008 (UTC)

Flickr (and other photo service) standard tags

I propose that we agree on a standard tagging system for identifying geohashing pictures on the various services. It would be fun to be able to quickly cull pictures from a certain day or graticle, and agreeing on tagging now means that we'll be able to automate such a search process later if someone has a particularly cunning plan.

A good system then would:

• keep track of day and graticule separately (for separate searching)
• indicate a standard tag for *all* geohashing pictures, regardless of day or graticle
• be deterministic and consistent
• be strictly alphanumeric (flickr strips all other characters and spaces when comparing)
• include something geohash-specific to keep non-geohashing noise out

Therefore, I suggest the following:

• All geohashing photos: geohashing
• Graticule tag: geohashing(N|S)##(E|W)###
• Date tag: geohashingYYYYMMDD
• Eg: This photo would get "geohashing", "geohashingN35W120", "geohashing20080524"

Thoughts, reactions, counter-proposals? --Psthomas 07:49, 27 May 2008 (UTC)

Sounds good to me. --Psud 12:45, 27 May 2008 (UTC)

Expedition archives

Is it possible to have a version of the expedition archives box at the top of each hash with options to go to the previous, current, and next geohash just for that graticule? Tytrain 23:11, 28 May 2008 (UTC)

Depends. Do you want to go through every possible date, or just selected ones (picking and choosing the ones that people actually went to)? One case is far easier than the other, and it's the one I used while making both Template:Date nav and Template:Expedition archive nav. --Tim P 07:12, 29 May 2008 (UTC)

Issue with the map

When I type the date 2008-06-01 into the map, I get the error "Market data is not available for 2008-06-30" However, I can type in 2008-05-32 and also 2008-05-33 and get coordinates. The 34th gives me "Market data is not available for 2008-06-02" (I'm looking at places east of -30°, by the way). Loggie 22:37, 30 May 2008 (UTC)

I get the same problem. BTW the coordinates returned for 2008-05-32 are *not* the correct coordinates for 2008-06-01, since it uses wrong date (2008-05-32) in the hash. Not sure if you realize this or are just pointing out more data -- at first I thought you had found a tricky workaround :)

Another observation, the page is also looking for DJI data on 2008-07-01, when I type in 2008-06-02, this is rather odd. --124.168.225.106 02:42, 31 May 2008 (UTC)

Possible Dangers of Geohashing

One problem I can see with geohashing is that in certain parts of the country, if the coordinates fall on someone's private property, you may be taking a risk of being shot on sight for trespassing. I believe that in some states, it might even be legal for landowners to do this, at least if they have warning signs posted on their property - although as an explorer, you can't necessarily depend on reliably being able to see the warning signs. Therefore, I would strongly advise all prospective geohashers to check their county's GIS for the land ownership records for their destination (and any properties that must be traversed to get there), and contact the landowner(s) and get permission to visit their property before heading out. --mpf