Changeset 2710 for inundation/utilities/numerical_tools.py

Timestamp:

Apr 12, 2006, 3:07:18 PM (19 years ago)

Author:

ole

Message:

Cleaned up in angle computation

File:

• inundation/utilities/numerical_tools.py (modified) (3 diffs)

inundation/utilities/numerical_tools.py

@@ -41 +41 @@
     # Compute angle
     p = innerproduct(v1, v2)
-    c = crossproduct_length(v1, v2)
+    c = innerproduct(v1, normal_vector(v2)) # Projection onto normal
+                                            # (negative cross product)
     
     theta = acos(p)
@@ -48 +49 @@
     # If v2 was the unit vector [1,0] this would correspond to the test
     # if v1[1] < 0: theta = 2*pi-theta    
-    # In general we use the sign of the cross product length
-    if c > 0: 
+    # In general we use the sign of the projection onto the normal.
+    if c < 0: 
        #Quadrant 3 or 4
        theta = 2*pi-theta        
@@ -82 +83 @@
 
     
-def crossproduct_length(v1, v2):
-    return v1[0]*v2[1]-v2[0]*v1[1]
+#def crossproduct_length(v1, v2):
+#    return v1[0]*v2[1]-v2[0]*v1[1]