增加了基于周围几个点差值求高程的功能。

dem.py

@@ -1,3 +1,6 @@
+import math
+
+import ezdxf
 from osgeo import gdal
 import numpy as np
 
@@ -50,8 +53,8 @@ class Dem:
         # print("\nThe 6 GeoTransform parameters of DEM are:\n", gt)
 
         N_site = site_latlng.shape[0]
-        Xgeo = site_latlng[:, 1]  # longitude
-        Ygeo = site_latlng[:, 0]  # latitude
+        Xgeo = site_latlng[:, 0]
+        Ygeo = site_latlng[:, 1]
         site_ele = np.zeros(N_site)
         for i in range(N_site):
             # Note:
@@ -72,7 +75,100 @@ class Dem:
             #
             #     [2] = 0 for north up DEM
             #     [4] = 0 for north up DEM
-            Xpixel = int(round((Xgeo[i] - gt[0]) / gt[1]))
-            Yline = int(round((Ygeo[i] - gt[3]) / gt[5]))
-            site_ele[i] = gdal_data.ReadAsArray(Xpixel, Yline, 1, 1).astype(np.float)
+            Xpixel = (Xgeo[i] - gt[0]) / gt[1]
+            Yline = (Ygeo[i] - gt[3]) / gt[5]
+            # 寻找左上，左下，右上，右下4个点
+            lu_xy = np.array([math.floor(Xpixel), math.floor(Yline)])  # 左上
+            ld_xy = np.array([math.floor(Xpixel), math.ceil(Yline)])  # 左下
+            ru_xy = np.array([math.ceil(Xpixel), math.floor(Yline)])  # 右上
+            rd_xy = np.array([math.ceil(Xpixel), math.ceil(Yline)])  # 右下
+            lu_elevation = gdal_data.ReadAsArray(
+                int(lu_xy[0]), int(lu_xy[1]), 1, 1
+            ).astype(float)
+            ld_elevation = gdal_data.ReadAsArray(
+                int(ld_xy[0]), int(ld_xy[1]), 1, 1
+            ).astype(float)
+            ru_elevation = gdal_data.ReadAsArray(
+                int(ru_xy[0]), int(ru_xy[1]), 1, 1
+            ).astype(float)
+            rd_elevation = gdal_data.ReadAsArray(
+                int(rd_xy[0]), int(rd_xy[1]), 1, 1
+            ).astype(float)
+            # delta_x = (Xpixel - ld_xy[0]) / 1  # 距离是1
+            # delta_y = (ld_xy[1]-Yline) / 1
+            # site_ele[i] = (
+            #     ld_elevation
+            #     + (lu_elevation - ld_elevation) * delta_y
+            #     + (rd_elevation - ld_elevation) * delta_x
+            #     + (ld_elevation - lu_elevation + ru_elevation - rd_elevation)
+            #     * delta_x
+            #     * delta_y
+            # )
+
+            # 通过空间平面方程乃拟合Z值
+            equa_a = np.array(
+                [
+                    [lu_xy[0], lu_xy[0] * lu_xy[1], lu_xy[1], 1],
+                    [ld_xy[0], ld_xy[0] * ld_xy[1], ld_xy[1], 1],
+                    [ru_xy[0], ru_xy[0] * ru_xy[1], ru_xy[1], 1],
+                    [rd_xy[0], rd_xy[0] * rd_xy[1], rd_xy[1], 1],
+                ]
+            )
+            equa_b = np.array(
+                [lu_elevation[0], ld_elevation[0], ru_elevation[0], rd_elevation[0]]
+            )
+            equa_c = np.linalg.solve(equa_a, equa_b)
+            point_z = (
+                Xpixel * equa_c[0]
+                + equa_c[1] * Xpixel * Yline
+                + equa_c[2] * Yline
+                + equa_c[3]
+            )
+            site_ele[i] = point_z
+            print(f"row:{Yline} col:{Xpixel}  elev:{site_ele[i]}")
         return site_ele
+
+
+def to_line_coordination(point_x_s, point_y_s, point_x_e, point_y_e):
+    path_length = ((point_x_s - point_x_e) ** 2 + (point_y_s - point_y_e) ** 2) ** 0.5
+    n = round(path_length / 1)
+    point_x = np.linspace(point_x_s, point_x_e, n, endpoint=True)
+    point_y = np.linspace(point_y_s, point_y_e, n, endpoint=True)
+    r = np.array([point_x, point_y]).transpose()
+    return r
+
+
+def distance(a, b):
+    r = np.sum((a - b) ** 2) ** 0.5
+    return r
+
+
+if __name__ == "__main__":
+    dem = Dem(r"e:\西北院\天都山750kV线路\天都山-妙岭卫片\ASC\tianmiaoN03-dem.tif")
+    dem.get_dem_info(if_print=True)
+    line_coordination = to_line_coordination(
+        573284.886, 4104898.933, 574543.845, 4105825.047
+    )
+    elevation = dem.get_elevation(line_coordination)
+
+    # fdsfd = np.array([
+    #     [573284.886, 4104898.933],
+    #     [573286.584, 4104900.182],
+    #     [573288.281, 4104901.431],
+    #     [573289.979 ,   4104902.68],
+    #     [573291.677 ,   4104903.929],
+    #     [573293.374 ,   4104905.178],
+    #
+    # ])
+    # elevation = dem.get_elevation(elevation)
+    doc = ezdxf.new(dxfversion="R2010")
+    msp = doc.modelspace()
+    x_axis = [0]
+    cord_0 = line_coordination[0, :]
+    for cord in line_coordination[1:]:
+        x_axis.append(distance(cord, cord_0))
+    msp.add_polyline2d(
+        [(x_axis[i] / 5, elevation[i] * 2) for i in range(len(elevation))]
+    )
+    doc.saveas("d.dxf")
+    print("Finished.")