Order polygon vertices clockwise ArcGIS Pro
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07-27-2024 12:43 PM
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I have a Python script that generates layout and I need to arrange the polygon vertices clockwise Like Image_1
my script to extract polygon vertices not clockwise.
def extract_polygon_vertices(feature_layer😞
results = []
with arcpy.da.SearchCursor(feature_layer, ["SHAPE@"]) as cursor:
for row in cursor:
geom = row[0]
if geom:
vertices = [(pnt.X, pnt.Y) for part in geom.getPart() for pnt in part if pnt]
vertices = order_vertices(vertices)
for i in range(len(vertices)):
if i > 0 and vertices[i] == vertices[i - 1]:
continue
pnt1 = vertices[i]
pnt2 = vertices[i - 1] if i > 0 else vertices[-1]
length = calculate_distance(pnt2, pnt1)
results.append((pnt1, pnt2, length))
else:
add_error_message("No geometry available.")
del cursor
return results
def order_vertices(vertices😞
"""
Order the vertices in a clockwise direction starting from the highest Y coordinate.
"""
if not vertices:
return []
ordered_vertices = []
# Get the highest Y coordinate
highest_y = max(vertices, key=lambda vertex: vertex[1])
highest_y_index = vertices.index(highest_y)
# Check if multiple points have the same highest Y and choose the most left one (smallest X)
top_points = [v for v in vertices if v[1] == highest_y[1]]
start_point = min(top_points, key=lambda vertex: vertex[0])
start_point_index = vertices.index(start_point)
# Order the points starting from start_point to the end, then from the beginning to start_point
ordered_vertices = vertices[start_point_index:] + vertices[:start_point_index]
return ordered_vertices
Image_2 : the incorrect ouptut
