投资问题，lingo程序

 

错误代码

model:
sets:
xishu/1..5/;
touzi/1..5/;
xinyong/1..5/;
qixian/1..5/;
link(xishu,touzi,xinyong,qixian):a,x,r,p;
endsets
data:
r=2 2 1 1 5;
p=9 15 4 3 2;
enddata
max=x1*0.043+x2*0.054+x3*0.05*x4*0.044+x5*0.045;
@sum(link:r*a)*x(i)/@sum(link:x)<=1.49;
@sum(link:p*a)*x(i)/@sum(link:x)<=5;
a2*x2+a3*x3+a4*x4>=400;
@sum(link:a)<=1000;
@for(link:@bin(a));

正确代码

model:
sets:
s/1..5/:a,b,c,x;
endsets
data:
a=2 2 1 1 5;
b=9 15 4 3 2;
c=4.3 5.4 5.0 4.4 4.5;
enddata
max=@sum(s:x*c/100)-0.5*(x(2)*c(2)+x(3)*c(3)+x(4)*c(4))/100;
@sum(s:a*x)/@sum(s:x)<=1.49;
@sum(s:b*x)/@sum(s:x)<=5;
x(2)+x(3)+x(4)>=400;
@sum(s:x)<=1000;
end

注意：link集合中各列必须属性相同，否则不能放到link中！