[GRASS-SVN] r55076 - in grass-addons/grass7/raster/r.agent: libagent tests

[svn_grass at osgeo.org]

Author: mic
Date: 2013-02-16 05:50:02 -0800 (Sat, 16 Feb 2013)
New Revision: 55076

Modified:
   grass-addons/grass7/raster/r.agent/libagent/playground.py
   grass-addons/grass7/raster/r.agent/tests/test_playground.py
Log:
adding halflife functionality for cell values

Modified: grass-addons/grass7/raster/r.agent/libagent/playground.py
===================================================================
--- grass-addons/grass7/raster/r.agent/libagent/playground.py	2013-02-16 07:59:19 UTC (rev 55075)
+++ grass-addons/grass7/raster/r.agent/libagent/playground.py	2013-02-16 13:50:02 UTC (rev 55076)
@@ -175,3 +175,21 @@
                                                     position[1]+1]))
         return positions
 
+    def decaycellvalues(self, layername, halflife, minimum=0):
+        """
+        Let the values in each cell decay, volatilize or evaporate over time
+        @param string layername name of the layer to work on
+        @param long halflife or number of years when to reach half of the value
+        @param long minimum value to keep on cell
+        """
+        if halflife > 0:
+            for i in range(self.region["rows"]):
+                for j in range(self.region["cols"]):
+                    if self.layers[layername][i][j] > minimum:
+                        v = int(round(
+                              self.layers[layername][i][j]*0.5**(1.0/halflife)))
+                        if v > minimum:
+                            self.layers[layername][i][j] = v
+                        else:
+                            self.layers[layername][i][j] = minimum
+

Modified: grass-addons/grass7/raster/r.agent/tests/test_playground.py
===================================================================
--- grass-addons/grass7/raster/r.agent/tests/test_playground.py	2013-02-16 07:59:19 UTC (rev 55075)
+++ grass-addons/grass7/raster/r.agent/tests/test_playground.py	2013-02-16 13:50:02 UTC (rev 55076)
@@ -111,5 +111,16 @@
         self.assertTrue(ps[2])
         self.assertFalse(ps[3])
 
+    def test_decaycellvalues(self):
+        l = "bar"
+        self.pg.createlayer(l)
+        self.pg.layers[l][0][0] = 100
+        self.pg.decaycellvalues(l, 3)
+        self.assertEqual(self.pg.layers[l][0][0], 79)
+        self.pg.decaycellvalues(l, 3)
+        self.assertEqual(self.pg.layers[l][0][0], 63)
+        self.pg.decaycellvalues(l, 3)
+        self.assertEqual(self.pg.layers[l][0][0], 50)
+
 #    def tearDown(self):