User:Sourcerer/KML tool

This calculator creates a KML file.

If Google Earth or another application that understands this file format is installed, it should launch and display the hashpoints for your specified date and graticule.

Bugs and requests

Please put bugs and requests on the discussion tab.

Usage

http://nbest.co.uk/kmlGeohash/index.php?date=2008-05-21&lat=52&lon=0&skins=2

• date - formatted yyyy-mm-dd - the default is today's date.
• lat - your graticule latitude - the default is 51 (Grenwich London).
• lon - your graticule longitude - the default is 0 (Grenwich London).
• skins - like an onion, the number of layers of points surrounding the home point - the default is 1 giving 9 hashpoints - the limits are 0 to 6.

Tests

• Test equator - Looks OK.
• Test round the back - The coordinates are shifted to prevent wrapping at +/- 179.999^o
• Australia - Australia looks OK.
• Atlanta - Atlanta looks OK.
• North pole - The coordinates are shifted to prevent wrapping at +/- 89.999^o
• South pole - The coordinates are shifted to prevent wrapping at +/- 89.999^o
• -50, -30 - South Georgia and Zavodovski islands look OK either side of 30W.
• Check that the 30W Time Zone Rule is correctly applied.

Source Code and Documentation

Source Code - Algorithm - 30W Time Zone Rule

Experiments

• {{#dow:2008|05|21}} -> 12824.94

• {{#md5:2008-05-21-{{#dow:2008|05|21}}|1|1}} -> 0.94961437806606
• {{#md5:2008-05-21-{{#dow:2008|05|21}}|2|1}} -> 0.36908385622475