写出A-star算法利用切比雪夫距离求出路径的matlab代码
时间: 2024-02-28 14:52:37 浏览: 85
A-star算法利用切比雪夫距离求出路径的MATLAB代码如下:
```matlab
function [path, cost] = astar_chebyshev(start_node, goal_node, obstacles)
% start_node: 起点
% goal_node: 终点
% obstacles: 障碍物,格式为 [x1, y1; x2, y2; ...]
% 计算起点到终点的切比雪夫距离
heuristic = @(node) chebyshev(node, goal_node);
% 初始化起点
start_node.g = 0;
start_node.f = heuristic(start_node);
% 初始化open表和closed表
open_list = [start_node];
closed_list = [];
% 开始搜索
while ~isempty(open_list)
% 选取f值最小的节点作为当前节点
[current_node, idx] = min([open_list.f]);
current_node = open_list(idx);
% 如果当前节点是目标节点,则返回路径
if isequal(current_node, goal_node)
path = trace_path(current_node);
cost = current_node.g;
return
end
% 将当前节点从open表中删除,并加入closed表
open_list(idx) = [];
closed_list(end+1) = current_node;
% 遍历当前节点的所有邻居
for neighbor = get_neighbors(current_node, obstacles)
% 如果邻居节点已经在closed表中,则跳过此节点
if ismember(neighbor, closed_list)
continue
end
% 计算邻居节点的g值
tentative_g = current_node.g + euclidean(current_node, neighbor);
% 如果邻居节点不在open表中,则将其加入open表
if ~ismember(neighbor, open_list)
neighbor.g = tentative_g;
neighbor.f = neighbor.g + heuristic(neighbor);
neighbor.parent = current_node;
open_list(end+1) = neighbor;
else
% 如果邻居节点已经在open表中,且新的g值更优,则更新其g值和父节点
idx = find(ismember(open_list, neighbor));
if tentative_g < open_list(idx).g
open_list(idx).g = tentative_g;
open_list(idx).f = open_list(idx).g + heuristic(open_list(idx));
open_list(idx).parent = current_node;
end
end
end
end
% 如果open表为空,说明找不到路径
path = [];
cost = Inf;
end
function h = chebyshev(node1, node2)
% 计算两个节点之间的切比雪夫距离
h = max(abs(node1.x - node2.x), abs(node1.y - node2.y));
end
function h = euclidean(node1, node2)
% 计算两个节点之间的欧几里得距离
h = norm([node1.x node1.y] - [node2.x node2.y]);
end
function path = trace_path(node)
% 从终点开始回溯,追踪路径
path = [node];
while isfield(node, 'parent')
node = node.parent;
path = [node path];
end
end
function neighbors = get_neighbors(node, obstacles)
% 获取节点的所有邻居
x = node.x;
y = node.y;
neighbors = [];
for dx = -1:1
for dy = -1:1
% 忽略当前节点
if dx == 0 && dy == 0
continue
end
% 计算邻居节点的位置
nx = x + dx;
ny = y + dy;
% 如果邻居节点在障碍物内,则跳过此节点
if ismember([nx ny], obstacles, 'rows')
continue
end
% 创建邻居节点
neighbor.x = nx;
neighbor.y = ny;
neighbors(end+1) = neighbor;
end
end
end
```
需要注意的是,在上述代码中,我同时实现了切比雪夫距离和欧几里得距离两种估价函数,可以通过修改函数句柄heuristic来选择使用哪种估价函数。另外,为了方便起见,我将节点的坐标和g值存储在结构体中,而不是使用矩阵。
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