User:Eupeodes/Geohashing Map/v1

Why another one

None of the calculators really worked like I wanted, so I decided to write my own based on the google maps API V3 and geo.crox.

Supported platforms

Desktop: (all?) modern browsers support on any OS
iPad and iPhone: Works very well with multi touch. Update November 28, 2013: with a bookmark on the homescreen created since today the adresbar and toolbar are hidden, resulting a larger map on the screen.
Android: Works both in native browser and others

Not tested

Blackberry, Windows phone, others not listed above

If anyone tests the app on any system, feel free to report if it works, either here (if it works) or on the discussion page (with bug report). Of course you can also join #geohashing on irc.foonetic.net

Features

Uses geolocation to determine location, also possible to provide url parameters or store home in a cookie
- When no location is provided the map will center on the Netherlands
Shows hash in home graticule + 8 surrounding graticules
Download 1 hash or all visible hashes as gpx
Select previous date, next date and today with buttons
When available not only the requested date but (optional) also a maximum of 6 days after that date is shown. Days are colored and the day of month is shown in the marker.
- When more than one date is selected all show up in the gpx
Display distance from home to hash in kilometers and miles
Clear message when hashes not yet available
Link to:
- the meetup on the wiki
- google maps driving directions
- Nearby geocaches
- Geohashing posters
Display streetview
Display global hash
Get permanent link from current view
Give name of location based on geonames.org
Short url's
Use a different center for the grid than home location (url parameters glat & glng define the centre of the grid)

Broken features

Send single hash to Garmin GPS device

Planned features

Expand to 5x5 hashes?

Want another feature? Feel free to ask on the discussion page. I don't promise I will do something with it, but I can take it into consideration. New features can also be discussed on #geohashing on irc.foonetic.net

Usage

Parameters:

lat - latitude of the initial graticule
lon or lng - longitude of the initial graticule
date - initial date in YYYY-MM-DD format
type - maptype, this has the following options:
- map - Roadmap
- sat - Satellite
- hyb - Hybrid roadmap/satellite (default)
- ter - terrain
zoom - zoom level of the map
clat & clng - where to center the map
multi - false to show only a single day

e.g: http://geohashing.info/?date=2005-05-26&lat=37&lon=-122

Short url's

There are also short url's available, the format of these url's is

http://geohashing.info[/type][/date[/single][/home[/zoom[/center]]]

type is one the types as above
date is date in YYYY-MM-DD or YYYYMMDD format
single is indicator for multi, 's' to show single day, otherwise leave out
home is geohash of the home location or 'global' to display the global
zoom is zoom level of the map
center is geohash of center of the map

Code

Below is the function that calculates the decimal part of the hash

<?php
class calc {
   public function doCalc($date, $dow){
       $md5 = md5($date."-".$dow);
       list($lat,$lng) = str_split($md5,16);
       return array($this->hex2dec($lat), $this->hex2dec($lng));
   }

   private function hex2dec($var){
       $o = 0;
       for($i=0;$i<16;$i++){
           $o += hexdec($var[$i])*pow(16,-$i-1);
       }
       return $o;
   }
}
?>

usage:

<?php
$calc = new calc();
list($lat, $lng) = $calc->doCalc($date, $dow);
?>

for $date the date of the hash should be filled in in the format yyyy-mm-dd
for $dow the dow that should be used should be filled in with a dot as decimal sign.