add definition of stone (=14 avoirdupois pounds, used in UK)

ddale · ddale · commit 8f5f87a35a2e · 2010-02-23T16:14:46.000-05:00
diff --git a/quantities/units/mass.py b/quantities/units/mass.py
@@ -37,6 +37,12 @@
     aliases=['pounds', 'avoirdupois_pound', 'avoirdupois_pounds'],
     doc='exact'
 )
+st = stone = UnitMass(
+    'stone',
+    14*lb,
+    symbol='st',
+    doc='As defined in the UK, 1 stone = 14 avoirdupois pounds'
+)
 
 carat = UnitMass(
     'carat',
