请编写一段最短路径matlab代码，要求能利用shp文件中的经纬度数据

由于没有提供具体的shp文件和起点终点坐标，以下代码只是提供一个最短路径的实现思路，并不能直接运行。

%读取shp文件中的经纬度数据
S = shaperead('filename.shp');
%获取点的坐标
lat = [S.Lat];
lon = [S.Lon];
%设置起点和终点的坐标
startLat = 30;
startLon = 120;
endLat = 31;
endLon = 121;
%计算起点和终点在点集中的位置
[startDist, startIndex] = min((lat - startLat).^2 + (lon - startLon).^2);
[endDist, endIndex] = min((lat - endLat).^2 + (lon - endLon).^2);
%构建邻接矩阵
n = length(lat);
adjMatrix = zeros(n);
for i = 1:n
for j = 1:n
dist = sqrt((lat(i)-lat(j))^2 + (lon(i)-lon(j))^2);
adjMatrix(i,j) = dist;
end
end
%使用Dijkstra算法计算最短路径
dist = inf(1,n);
prev = zeros(1,n);
visited = false(1,n);
dist(startIndex) = 0;
for i = 1:n
[minDist, u] = min(dist);
visited(u) = true;
if u == endIndex
break;
end
for v = 1:n
if adjMatrix(u,v) > 0 && ~visited(v)
alt = dist(u) + adjMatrix(u,v);
if alt < dist(v)
dist(v) = alt;
prev(v) = u;
end
end
end
end
%构造最短路径
path = [endIndex];
while prev(path(1)) ~= 0
path = [prev(path(1))), path];
end
path = [startIndex, path];
%绘制最短路径
plot(lon(lat),lat,'bo');
hold on;
plot(lon(path),lat(path),'r-');
hold off;