将高程等值线导出到 DXF 时连接线错误

Question

我正在寻求帮助以解决从数据框中导出轮廓线的问题。

我的目标是获得一个 DXF 文件，以如下所示的方式表示高程等高线： 所需输出

但是，我得到了这个： 实际输出（错误连接的线）

这就是输入格式：

X（东距）	Y（北移）	Z（海拔高度，单位：米）
312581.9	6457327.5	84.88
...	...	...

这是我的代码：

import numpy as np
import matplotlib.pyplot as plt
from scipy.interpolate import griddata
import ezdxf

# See input format in the table above. 

# Extract the x, y, z columns
x = cut_out_df['x'].values
y = cut_out_df['y'].values
z = cut_out_df['z'].values

# Create a grid to interpolate the data
grid_x, grid_y = np.mgrid[min(x):max(x):200j, min(y):max(y):200j]  # Grid with 200x200 resolution
grid_z = griddata((x, y), z, (grid_x, grid_y), method='linear')  # Interpolation

# Create the contour lines
contour_levels = np.linspace(np.min(grid_z), np.max(grid_z), 10)  # Define contour levels
contour_data = ax.contour(grid_x, grid_y, grid_z, levels=contour_levels)

# Export contour data to DXF
doc = ezdxf.new()

# Create a new model space in the DXF document
msp = doc.modelspace()

# Iterate through the contour collections
for level, collection in zip(contour_levels, contour_data.collections):
    # Get the paths of the contour lines
    for path in collection.get_paths():
        vertices = path.vertices
        # Create a polyline for each contour line
        polyline = msp.add_lwpolyline(vertices, close=False)
        # Add a layer or set a specific attribute to identify the contour level
        polyline.dxf.layer = f'Contour_{level:.2f}'
        
# Save the DXF document
doc.saveas('contours.dxf')

我认为

close=False

可以解决问题，但后来意识到可以有多个相同海拔高度的“岛屿”。它们实际上是独立的实体。

Answer 1

再次感谢mozman给出最初的提示。

我可以通过以下方式解决这个问题：

# Code as above 

doc = ezdxf.new()
msp = doc.modelspace()

for level, collection in zip(contour_levels, contour_data.collections):
    for path in collection.get_paths():
        for segment in path.to_polygons():
            if len(segment) > 1:
                vertices_3d = [(x, y, level) for x, y in segment]
                if np.allclose(vertices_3d[0], vertices_3d[-1]):
                    vertices_3d.pop()

                polyline = msp.add_polyline3d(vertices_3d)
                polyline.dxf.layer = f'Contour_{level:.2f}'

使用

if np.allclose(vertices_3d[0], vertices_3d[-1]):

检查，然后使用

vertices_3d.pop()

确实可以删除导出中始终连接的点。