【python】通行网格地图四叉树化
受到Leecode 427题的启发，427. 建立四叉树
想将由0和1组成的网格地图绘制为四叉树地图，0表示可通行网格，1表示不可通行网格。
import matplotlib.pyplot as plt
import matplotlib.patches as patches
import numpy as np
from matplotlib import colors class Node: def __init__(self, x0, y0, w, h, data): self.x0 = x0 self.y0 = y0 self.width = w self.height = h self.data = data self.children = [] self.passable = np.sum(data == 1) / (w * h) <= 0.9 # 障碍物比例<= 0.2 可通行 class QuadTree: def __init__(self, x, y, w, h, data): self.root = Node(x, y, w, h, data) self.root.passable = True if self.root.passable: self.subdivide(self.root) def subdivide(self, node): x, y, w, h = node.x0, node.y0, node.width // 2, node.height // 2# Divide the node's data into quadrantsdata_quadrants = [ node.data[0:h, 0:w], node.data[h: node.height, 0:w], node.data[0:h, w:node.width], node.data[h:node.height, w:node.width] ] for i, data in enumerate(data_quadrants): width = w height = h if (i // 2): width = node.width - w if (i % 2): height = node.height - h child = Node(x + (i // 2) * w, y + (i % 2) * h, width, height, data) node.children.append(child) if len(np.unique(data)) > 1 and w > 1 and h > 1: self.subdivide(child) def draw(self, ax): def _draw(node): color = 'black' if not node.passable else 'white' # ax.add_patch(patches.Rectangle((node.x0, node.y0), node.width, node.height, facecolor=color, edgecolor='black')) ax.add_patch( patches.Rectangle((node.x0, node.y0), node.width, node.height, facecolor=color, edgecolor='black')) for child in node.children: if child is not None: _draw(child) _draw(self.root) def print_leaves(self, node=None): if node is None: node = self.root if all(child is None for child in node.children): print( f"Leaf Node: x={node.x0}, y={node.y0}, width={node.width}, height={node.height}, passable={node.passable}") else: for child in node.children: if child is not None: self.print_leaves(child) # Create a 32x32 grid map with random obstacles
map_data = np.loadtxt("./map_txt/Random_32x32_.2.txt") width, height = map_data.shape # Create a quadtree
qt = QuadTree(0, 0, width, height, map_data) cmap = colors.ListedColormap(['white', 'black', ]) # Draw the original map
fig, axs = plt.subplots(1, 2, figsize=(10, 5))
axs[0].imshow(map_data, cmap=cmap, origin='lower')
axs[0].set_title('Original Map') # Draw the quadtree
axs[1].set_xlim(0, width)
axs[1].set_ylim(0, height)
qt.draw(axs[1])
axs[1].set_title('Quadtree Map') plt.show()
运行结果
