www.gusucode.com > 无线传感器网络定位算法 matlab源代码 包含七个算法matlab源码程序 > Localization/MDS-MAP/MDS_MAP.m

    function MDS_MAP(dist_available)
% MDS_MAP Alg. Zenzon Don  5.12.2010
% dist_available:节点间的距离是否可以获得  true-available  false-unavailable
%~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    load '../Deploy Nodes/coordinates.mat';
    load '../Topology Of WSN/neighbor.mat'; 
    if all_nodes.anchors_n<3
        disp('锚节点少于3个,MDS_MAP算法无法执行');
        return;
    end
    %~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    %shortest_path_hop:以跳数计的邻接矩阵
    %shortest_path_dist:以距离计的邻接矩阵
    %shortest_path:当距离可测时，等于shortest_path_dist;否则为shortest_path_hop
    shortest_path_hop=neighbor_matrix;
    shortest_path_hop=shortest_path_hop+eye(all_nodes.nodes_n)*2;
    shortest_path_hop(shortest_path_hop==0)=Inf;
    shortest_path_hop(shortest_path_hop==2)=0;
    directory=cd;
    cd(['../Topology Of WSN/Transmission Model/',model]);
    shortest_path_dist=ones(size(neighbor_rss));
    try
        shortest_path_dist(neighbor_matrix==1)=rss2dist(neighbor_rss(neighbor_matrix==1),1);
    catch
        shortest_path_dist(neighbor_matrix==1)=rss2dist(neighbor_rss(neighbor_matrix==1));
    end
    shortest_path_dist=shortest_path_dist-eye(size(neighbor_rss));
    shortest_path_dist(shortest_path_dist==1)=Inf;
    cd(directory);
    if dist_available
        shortest_path=shortest_path_dist;
    else
        shortest_path=shortest_path_hop;
    end
    %~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    % 执行Floyd算法，算出任意两个点的最短距离(根据dist_available，以跳数计或者以距离计)
    for k=1:all_nodes.nodes_n
        for i=1:all_nodes.nodes_n
            for j=1:all_nodes.nodes_n
                if shortest_path(i,k)+shortest_path(k,j)<shortest_path(i,j)%min(h(i,j),h(i,k)+h(k,j))
                    shortest_path(i,j)=shortest_path(i,k)+shortest_path(k,j);
                end
            end
        end
    end
    if length(find(shortest_path==Inf))~=0
        disp('网络不连通...需要划分连通子图...这里没有考虑这种情况');
        return;
    end
    %~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    % 对最短距离矩阵shortest_path执行MDS方法
    J=eye(all_nodes.nodes_n)-ones(all_nodes.nodes_n)/all_nodes.nodes_n;
    H=-0.5*J*shortest_path.^2*J;
    [V S T]=svd(H);
    X=T*sqrt(S);
    relative_map=X(:,1:2);
    save maps_and_all_nodes.mat relative_map all_nodes;    
    %~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    warning off;
    disp('时间可能很长，可以先去上个厕所');
    disp('如果回来还在跑，那么可以调下参数，把TolX和TolFun后面的参数调大e.g0.01,把 MaxIter和MaxFunEvals改成10000吧');
    [q r]=fsolve('relative_to_absolute',[1,1,0,0,all_nodes.square_L/2,all_nodes.square_L/2],optimset('Display','off','TolX',0.001,'TolFun',0.001,'MaxIter',inf,'MaxFunEvals',inf));
    q
    absolute_map=relative_map*[q(1)*cos(q(3)) q(2)*sin(q(4));-q(1)*sin(q(3)) q(2)*cos(q(4))]+repmat([q(5) q(6)],all_nodes.nodes_n,1);
    save maps_and_all_nodes.mat absolute_map -APPEND;
    all_nodes.estimated(all_nodes.anchors_n+1:all_nodes.nodes_n,:)=absolute_map(all_nodes.anchors_n+1:all_nodes.nodes_n,:);
    all_nodes.anc_flag(all_nodes.anchors_n+1:all_nodes.nodes_n)=2;
    save '../Localization Error/result.mat' all_nodes comm_r;
end