a星算法matlab代码
时间: 2024-03-03 07:45:30 浏览: 218
A*算法是一种常用的路径搜索算法,用于在图或网络中找到最短路径。下面是一个简单的A*算法的Matlab代码示例:
```matlab
function path = AStar(startNode, goalNode, graph)
% 初始化openSet和closedSet
openSet = startNode;
closedSet = [];
% 初始化起始节点的代价和启发式估计值
startNode.gCost = 0;
startNode.hCost = heuristic(startNode, goalNode);
startNode.fCost = startNode.gCost + startNode.hCost;
while ~isempty(openSet)
% 从openSet中选择fCost最小的节点
currentNode = openSet(1);
currentIndex = 1;
for i = 1:length(openSet)
if openSet(i).fCost < currentNode.fCost
currentNode = openSet(i);
currentIndex = i;
end
end
% 如果当前节点是目标节点,返回路径
if currentNode == goalNode
path = reconstructPath(currentNode);
return;
end
% 将当前节点从openSet中移除,并加入closedSet
openSet(currentIndex) = [];
closedSet = [closedSet, currentNode];
% 遍历当前节点的邻居节点
neighbors = getNeighbors(currentNode, graph);
for i = 1:length(neighbors)
neighbor = neighbors(i);
% 如果邻居节点已经在closedSet中,跳过
if ismember(neighbor, closedSet)
continue;
end
% 计算邻居节点的代价和启发式估计值
tentativeGCost = currentNode.gCost + distance(currentNode, neighbor);
if ~ismember(neighbor, openSet) || tentativeGCost < neighbor.gCost
neighbor.gCost = tentativeGCost;
neighbor.hCost = heuristic(neighbor, goalNode);
neighbor.fCost = neighbor.gCost + neighbor.hCost;
neighbor.parent = currentNode;
% 如果邻居节点不在openSet中,加入openSet
if ~ismember(neighbor, openSet)
openSet = [openSet, neighbor];
end
end
end
end
% 如果openSet为空,表示无法找到路径
error("No path found.");
end
function h = heuristic(node1, node2)
% 启发式函数,计算两个节点之间的估计距离
h = sqrt((node1.x - node2.x)^2 + (node1.y - node2.y)^2);
end
function d = distance(node1, node2)
% 计算两个节点之间的实际距离
d = sqrt((node1.x - node2.x)^2 + (node1.y - node2.y)^2);
end
function path = reconstructPath(node)
% 从目标节点开始,逆向构建路径
path = [];
while ~isempty(node.parent)
path = [node, path];
node = node.parent;
end
end
function neighbors = getNeighbors(node, graph)
% 获取当前节点的邻居节点
neighbors = [];
for i = 1:length(graph)
if graph(node, i) == 1
neighbors = [neighbors, i];
end
end
end
```
这段代码实现了A*算法的基本逻辑,包括初始化openSet和closedSet、计算节点的代价启发式估计值、选择fCost最小的节点、更新节点的代价和启发式估计值等。你可以根据自己的需求进行修改和扩展。
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