Changeset 1024

Timestamp:

Mar 7, 2005, 3:15:02 PM (20 years ago)

Author:

ole

Message:

Added function outside_polygon and a test

Location:

inundation/ga/storm_surge/pyvolution

Files:

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

inundation/ga/storm_surge/pyvolution/test_util.py

@@ -919 +919 @@
         assert allclose( res, [0,1,2] )
 
+    def test_outside_polygon(self):
+
+        U = [[0,0], [1,0], [1,1], [0,1]] #Unit square    
+        assert not outside_polygon( [0.5, 0.5], U )
+        #evaluate to False as the point 0.5, 0.5 is inside the unit square
+
+        assert outside_polygon( [1.5, 0.5], U )
+        #evaluate to True as the point 1.5, 0.5 is outside the unit square
+       
+        indices = outside_polygon( [[0.5, 0.5], [1, -0.5], [0.3, 0.2]], U )
+        assert allclose( indices, [1] )
+        
+        #One more test of vector formulation returning indices
+        polygon = [[0,0], [1,0], [0.5,-1], [2, -1], [2,1], [0,1]]
+        points = [ [0.5, 0.5], [1, -0.5], [1.5, 0], [0.5, 1.5], [0.5, -0.5]]
+        res = outside_polygon( points, polygon )
+
+        assert allclose( res, [3,4] )
+
+
+
+        polygon = [[0,0], [1,0], [0.5,-1], [2, -1], [2,1], [0,1]]
+        points = [ [0.5, 1.4], [0.5, 0.5], [1, -0.5], [1.5, 0], [0.5, 1.5], [0.5, -0.5]]
+        res = outside_polygon( points, polygon )
+
+        assert allclose( res, [0, 4, 5] )        
+        
 
     def test_populate_polygon(self):

inundation/ga/storm_surge/pyvolution/util.py

@@ -918 +918 @@
        
     Examples:
-       inside_polygon( [0.5, 0.5], [[0,0], [1,0], [1,1], [0,1]] )
+       U = [[0,0], [1,0], [1,1], [0,1]] #Unit square
+       inside_polygon( [0.5, 0.5], U)
        will evaluate to True as the point 0.5, 0.5 is inside the unit square 
        
-       inside_polygon( [[0.5, 0.5], [1, -0.5], [0.3, 0.2]] )
+       inside_polygon( [[0.5, 0.5], [1, -0.5], [0.3, 0.2]], U)
        will return the indices [0, 2] as only the first and the last point 
        is inside the unit square
@@ -1075 +1076 @@
         return indices[:count]
 
+
+#def remove_from(A, B):
+#    """Assume that A
+#    """
+#    from Numeric import search_sorted##
+#
+#    ind = search_sorted(A, B)
+
+    
+
+def outside_polygon(point, polygon, closed = True, verbose = False):
+    """Determine whether points are outside a polygon
+    
+    Input:
+       point - Tuple of (x, y) coordinates, or list of tuples
+       polygon - list of vertices of polygon
+       closed - (optional) determine whether points on boundary should be 
+       regarded as belonging to the polygon (closed = True) 
+       or not (closed = False) 
+    
+    Output:
+       If one point is considered, True or False is returned.
+       If multiple points are passed in, the function returns indices 
+       of those points that fall outside the polygon     
+       
+    Examples:
+       U = [[0,0], [1,0], [1,1], [0,1]] #Unit square    
+       outside_polygon( [0.5, 0.5], U )
+       will evaluate to False as the point 0.5, 0.5 is inside the unit square
+
+       ouside_polygon( [1.5, 0.5], U )
+       will evaluate to True as the point 1.5, 0.5 is outside the unit square
+       
+       outside_polygon( [[0.5, 0.5], [1, -0.5], [0.3, 0.2]], U )
+       will return the indices [1] as only the first and the last point 
+       is inside the unit square
+    """
+
+    res  = inside_polygon(point, polygon, closed, verbose)
+
+    if res is True or res is False:
+        return not res
+
+    #Now invert indices
+    from Numeric import arrayrange, compress
+    outside_indices = arrayrange(len(point))
+    for i in res:
+        outside_indices = compress(outside_indices != i, outside_indices)
+    return outside_indices
+
+
+
 class Polygon_function:
     """Create callable object f: x,y -> z, where a,y,z are vectors and