graphy_plot.asv

最近一段数学建模源程序汇编,适用于建模初学者练习

clf,
A=[0 1 1 0;0 0 1 1;0 0 0 1;1 0 0 0];%输入邻接矩阵
xy=[0 1;0 0;-1 -0.5;1 -0.5];%顶点坐标
l=1;%控制参数，l=0，画无向图；l~=0，画有向图
p=0.4%控制箭头大小的参数
%graphy_plot(A,xy,1,0.5),
%function y=graphy_plot(A,xy,l,p)
%画矩阵的有向结构图，A为邻接矩阵，xy为顶点坐标，l为控制参数，l=0，画无向图；l~=0，
%画有向图。p为控制箭头大小的参数。
a=-max(abs(xy(:,1)))*1.1;b=max(abs(xy(:,1)))*1.1;
c=-max(abs(xy(:,2)))*1.1;d=max(abs(xy(:,2)))*1.2;
if l==0
    gplot(A,xy),axis([a b c d]),hold on,
else if l~=0
        U=[ ];V=[ ];X=[ ];Y=[ ];
        n=length(A(:,1));
        for i=1:n
            k=find(A(i,:)~=0);
            m=length(k);
            if(m~=0)
                for j=1:m
                    u(1)=(xy(k(j),1)-xy(i,1));v(1)=(xy(k(j),2)-xy(i,2));
                    u(2)=eps; v(2)=eps;U=[u;U];V=[v;V];
                    X=[[xy(i,1) xy(k(j),1)];X];     Y=[[xy(i,2) xy(k(j),2)];Y];
                end
                %switch i
                %  case 1
                        text(xy(i,1),xy(i,2),['\bullet\leftarrow\fontsize{16}\it{U}',num2str(i)]);
                     case 2
                         text(xy(i,1),xy(i,2),['\bullet\leftarrow\fontsize{16}\it{V}',num2str(i)]);
                         case 3
                             text(xy(i,1),xy(i,2),['\bullet\leftarrow\fontsize{16}\it{X}',num2str(i)]);
                               case 4
                                   text(xy(i,1),xy(i,2),['\bullet\leftarrow\fontsize{16}\it{Y}',num2str(i)]);
                           end
                hold on,
            end
        end
        gplot(A,xy),axis([a b c d]),hold on,
        h=quiver(X,Y,U,V,p);set(j,'color','red');hold on,
        plot(xy(:,1),xy(:,2),'k','markersize',12),hold on,
    end
   hold off
end