whk_f.m

魏海坤编著的《神经网络结构设计的理论与方法》 国防工业出版社出版

function main()
N=10;
A=1.5;
D=1;
u0=0.02;
Step_t=0.1;
MaxEpochs=2000;

% 得到城市间距离矩阵
CityCood=rand(2,N);
DistanceMat=dist(CityCood',CityCood);

U=0.2*rand(N,N)-0.1;
for Count=1:MaxEpochs
    V=(1+tansig(U/u0))/2;
    E=CacuEnergy(V,DistanceMat,A,D)
    
    delta_U=CacuDeltaU(V,DistanceMat,A,D,Step_t);
    U=U+delta_U*Step_t;
end
[NewV,CheckRes]=RouteCheck(V);
if(CheckRes<1)
    FinalE=CacuEnergy(NewV,DistanceMat,A,D)
    RouteLen=TotalRouteLength(NewV,CityCood)
    PlotRoute(NewV,CityCood);
else
    disp('路径无效!!'),
end

% 能量计算
function E=CacuEnergy(V,d,A,D)
[n,n]=size(V);
t1=sumsqr(sum(V,2)-1);
t2=sumsqr(sum(V,1)-1);
PermitV=V(:,2:n);
PermitV=[PermitV V(:,1)];
temp=d*PermitV;
t3=sum(sum(V.*temp))
E=0.5*(A*t1+A*t2+D*t3);

% 计算U的增量
function d_U=CacuDeltaU(V,d,A,D,dt)
[n,n]=size(V);
t1=repmat(sum(V,2)-1,1,n);
t2=repmat(sum(V,1)-1,n,1);
PermitV=V(:,2:n);
PermitV=[PermitV V(:,1)];
t3=d*PermitV;
d_U=-dt*(A*t1+A*t2+D*t3);

% 检查V是否是有效途径
function [NewV,CheckRes]=RouteCheck(V)
[rows,columns]=size(V);
NewV=zeros(rows,columns);
[XC,Order]=max(V);
for j=1:columns,
    NewV(Order(j),j)=1;
end
SC=sum(NewV);
SR=sum(NewV');
CheckRes=sumsqr(SC-SR);

% 绘制路径
function PlotRoute(V,CityCood)
figure;
title('TSP solution');
xlabel('X坐标');
ylabel('Y坐标');
axis([0,1,0,1])
axis on
[xxx,order]=max(V);
NewCood=CityCood(:,order);
NewCood=[NewCood NewCood(:,1)];
plot(NewCood(1,:),NewCood(2,:),'o-');

% 计算路径实际长度
function Len=TotalRouteLength(V,CityCood)
[xxx,order]=max(V);
NewCood=CityCood(:,order);
NewCood=[NewCood NewCood(:,1)];
[rows,columns]=size(NewCood);
Len=0;
for i=2:columns,
    Len=Len+dist(NewCood(:,i-1)',NewCood(:,i));
end