http://www.mediawiki.org/wiki/Special:Code/pywikipedia/11682
Revision: 11682
Author: legoktm
Date: 2013-06-21 19:26:19 +0000 (Fri, 21 Jun 2013)
Log Message:
-----------
Implement experimental and untested dimToPrecision function
Modified Paths:
--------------
branches/rewrite/pywikibot/__init__.py
Modified: branches/rewrite/pywikibot/__init__.py
===================================================================
--- branches/rewrite/pywikibot/__init__.py 2013-06-21 18:27:24 UTC (rev
11681)
+++ branches/rewrite/pywikibot/__init__.py 2013-06-21 19:26:19 UTC (rev
11682)
@@ -12,6 +12,7 @@
import datetime
import difflib
import logging
+import math
import re
import sys
import threading
@@ -168,9 +169,28 @@
globes[data['globe']], site=site)
def dimToPrecision(self):
- """Convert dim from GeoData to Wikibase's Precision"""
- raise NotImplementedError
+ """Convert dim from GeoData to Wikibase's Precision
+ Formula from http://williams.best.vwh.net/avform.htm#LL and
+
http://gis.stackexchange.com/questions/2951/algorithm-for-offsetting-a-latitude-longitude-by-some-amount-of-meters
+
+ THIS FUNCTION IS EXPERIMENTAL DO NOT USE IT!
+ """
+ lat_r = math.radians(self.lat)
+ lon_r = math.radians(self.lon)
+ radius = 6378137 # TODO: Support other globes
+ offset = self.dim
+ d_lat_r = offset / radius
+ d_lon_r = offset / (radius * math.cos(math.pi * lat_r / 180))
+
+ # Now convert to degrees
+ lat_offset = math.degrees(d_lat_r)
+ lon_offset = math.degrees(d_lon_r)
+
+ # Take the average
+ avg_offset = (lat_offset + lon_offset) / 2.0
+ self.precision = avg_offset
+
def precisionToDim(self):
"""Convert precision from Wikibase to GeoData's dim"""
raise NotImplementedError
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