[GRASS-SVN] r40801 - grass-addons/gui/wxpython/data_catalog

[svn_grass at osgeo.org]

Author: rashadkm
Date: 2010-02-03 14:41:24 -0500 (Wed, 03 Feb 2010)
New Revision: 40801

Added:
   grass-addons/gui/wxpython/data_catalog/units.py
Log:
fixed units.py

Added: grass-addons/gui/wxpython/data_catalog/units.py
===================================================================
--- grass-addons/gui/wxpython/data_catalog/units.py	                        (rev 0)
+++ grass-addons/gui/wxpython/data_catalog/units.py	2010-02-03 19:41:24 UTC (rev 40801)
@@ -0,0 +1,118 @@
+"""!
+ at package units
+
+ at brief Units management
+
+Probably will be replaced by Python SWIG fns in the near future(?)
+
+Usage:
+
+ at code
+from units import Units
+ at endcode
+
+Classes:
+ - BaseUnits
+
+(C) 2009 by the GRASS Development Team
+
+This program is free software under the GNU General Public
+License (>=v2). Read the file COPYING that comes with GRASS
+for details.
+
+ at author Martin Landa <landa.martin gmail.com>
+"""
+
+class BaseUnits:
+    def __init__(self):
+        self._units = dict()
+        self._units['length'] = { 0 : { 'key' : 'mu', 'label' : _('map units') },
+                             1 : { 'key' : 'me', 'label' : _('meters') },
+                             2 : { 'key' : 'km', 'label' : _('kilometers') },
+                             3 : { 'key' : 'mi', 'label' : _('miles') },
+                             4 : { 'key' : 'ft', 'label' : _('feet') } }
+        
+        self._units['area']   = { 0 : { 'key' : 'mu', 'label' : _('sq map units') },
+                             1 : { 'key' : 'me', 'label' : _('sq meters') },
+                             2 : { 'key' : 'km', 'label' : _('sq kilometers') },
+                             3 : { 'key' : 'ar', 'label' : _('acres') },
+                             4 : { 'key' : 'ht', 'label' : _('hectares') } }
+
+    def GetUnitsList(self, type):
+        """!Get list of units (their labels)
+        
+        @param type units type ('length' or 'area')
+        
+        @return list of units labels
+        """
+        result = list()
+        try:
+            keys = self._units[type].keys()
+            keys.sort()
+            for idx in keys:
+                result.append(self._units[type][idx]['label'])
+        except KeyError:
+            pass
+        
+        return result
+
+    def GetUnitsKey(self, type, index):
+        """!Get units key based on index
+        
+        @param type units type ('length' or 'area')
+        @param index units index
+        """
+        return self._units[type][index]['key']
+
+    def GetUnitsIndex(self, type, key):
+        """!Get units index based on key
+        
+        @param type units type ('length' or 'area')
+        @param key units key, e.g. 'me' for meters
+
+        @return index
+        """
+        for k, u in self._units[type].iteritems():
+            if u['key'] == key:
+                return k
+        return 0
+
+Units = BaseUnits()
+
+def ConvertValue(value, type, units):
+    """!Convert value from map units to given units
+
+    Inspired by vector/v.to.db/units.c
+
+    @param value value to be converted
+    @param type units type ('length', 'area')
+    @param unit  destination units
+    """
+    # get map units
+    # TODO
+    
+    f = 1
+    if type == 'length':
+        if units == 'me':
+            f = 1.0
+        elif units == 'km':
+            f = 1.0e-3
+        elif units == 'mi':
+            f = 6.21371192237334e-4
+        elif units == 'ft':
+            f = 3.28083989501312
+    else: # -> area
+        if units == 'me':
+            f = 1.0
+        elif units == 'km':
+            f = 1.0e-6
+        elif units == 'mi':
+            f = 3.86102158542446e-7
+        elif units == 'ft':
+            f = 10.7639104167097
+        elif units == 'ar':
+            f = 2.47105381467165e-4
+        elif units == 'ht':
+            f = 1.0e-4
+
+    return f * value