输入数据是由两个或多个二维点组成的线数组:
coordinates = [(x, y, x1, y1, x2, y2, etc.), (x3, y3, x4, y4, etc.)].
这里是所有坐标:https://pastebin.com/raw/uj71Wz0U.
问题是找到图中所有的无弦循环。我们需要考虑到弦不仅可以在图形的点之间绘制,还可以例如从一条线的中间到另一条线的中间绘制。
我的图中只有 15 个这样的循环:
我尝试过使用networkx的无弦循环方法,但我还没有找到专门适合我的情况的方法。
这是一段代码,可帮助绘制我上面指定的坐标处的所有线条:
# Create coordinate lists for each pair of points
x_coords = []
y_coords = []
all_connections = []
for coord_set in coords:
x_pair = []
y_pair = []
connections_pair = []
for i in range(len(coord_set) // 2 - 1):
x1, y1 = coord_set[2*i], coord_set[2*i+1]
x2, y2 = coord_set[2*i+2], coord_set[2*i+3]
x_pair.extend([x1, x2])
y_pair.extend([y1, y2])
connections_pair.append(((x1, y1), (x2, y2))))
all_connections.append(((x1, y1), (x2, y2))))
x_coords.append(x_pair)
y_coords.append(y_pair)
print(all_connections)
# Plot the graph
for i in range(len(x_coords)):
plt.plot(x_coords[i], y_coords[i], marker='o')
plt.xlabel('X')
plt.ylabel('Y')
plt.title('Line Chart')
plt.grid(True)
plt.show()
假设输入中指定了每条线交点的坐标:
- Construct undirected graph.
( Vertices are specified in the input. Edges are lines between vertices. )
- Construct empty list of polygons
- Loop over every vertex specified in the input
- Check if it is a member of a polygon
( is there a path from the vertex that loops back again to the starting vertex.
Any decent graph theory library will give you a method to do this. )
- If polygon is unique, add to list of polygons
- Loop over vertices
- Loop over list of polygons
- IF vertex NOT part of polygon
- IF vertex INSIDE polygon
( algorithm https://ravenspoint.wordpress.com/2010/06/27/in-or-out/ )
- REMOVE polygon from list of polygons
( careful not to invalidate loop iterator )
请注意,如果线 can 交叉而没有输入指定的坐标,则必须检查属于多边形的每对线是否相交(任何计算几何文本将提供算法)并删除两个多边形重叠的)