Changeset 7695 for anuga_core/source/anuga/abstract_2d_finite_volumes

Timestamp:

Apr 23, 2010, 10:15:46 PM (14 years ago)

Author:

hudson

Message:

calc_bearing handles cases where the speed is zero, and outputs NaN.

Location:

anuga_core/source/anuga/abstract_2d_finite_volumes

Files:

• test_util.py (modified) (1 diff)
• util.py (modified) (2 diffs)

anuga_core/source/anuga/abstract_2d_finite_volumes/test_util.py

@@ -1626 +1626 @@
         assert v==1
        
-
+    def test_calc_bearings_zero_vector(self): 
+        from math import atan, degrees
+
+        uh = 0
+        vh = 0
+        angle = calc_bearing(uh, vh)
+
+        assert angle == NAN
+        
 #-------------------------------------------------------------
 

anuga_core/source/anuga/abstract_2d_finite_volumes/util.py

@@ -14 +14 @@
 from shutil import copy
 
-from anuga.utilities.numerical_tools import ensure_numeric, angle
+from anuga.utilities.numerical_tools import ensure_numeric, angle, NAN
 
 from math import sqrt, atan, degrees
@@ -300 +300 @@
     # * moving the reference direction from [1,0] to North
     # * changing from counter clockwise to clocwise.
+
+    # if indeterminate, just return 
+    if uh==0 and vh==0:
+        return NAN
     
     return degrees(angle([uh, vh], [0, -1]))