Question

急！那位高手帮忙看下这个lingo程序，错在什么地方了？

model:
min=5000*@if(x31-x41#ge#0,0,x41-x31)+2250*2*x41+(y41-750)*2*2.7*x41+1600*@if(x32-x42#ge#0,0,x42-x32)+1800*2*x42+(y42-1000)*2*2.2*x42+2400*@if(x33-x43#ge#0,0,x43-y33)+3750*2*x43+(y43-1200)*2*1.8*x43+1200*@if(x34-x44#ge#0,0,x44-x34)+4800*2*x44+(y44-1800)*2*3.8*x44+5000*@if(x41-x51#ge#0,0,x51-x41)+2250*4*x51+(y51-750)*4*2.7*x51+1600*@if(x42-x52#ge#0,0,x52-x42)+1800*4*x52+(y52-1000)*4*2.2*x52+2400*@if(x43-x53#ge#0,0,x53-x43)+3750*4*x53+(y53-1200)*4*1.8*x53+1200*@if(x44-x54#ge#0,0,x54-x44)+4800*4*x54+(y54-1800)*4*3.8*x54;
x31*y31+x32*y32+x33*y33+x34*y34>=25000;
x41*y41+x42*y42+x43*y43+x44*y44>=36000;
x51*y51+x52*y52+x53*y53+x54*y54>=25000;
x31>=0;x31<=10;y31>=750;y31<=1750;
x32>=0;x32<=4;y32>=1000;y32<=1500;
x33>=0;x33<=8;y33>=1200;y33<=2000;
x34>=0;x34<=3;y34>=1800;y34<=3500;
x41>=0;x41<=10;y41>=750;y41<=1750;
x42>=0;x42<=4;y42>=1000;y42<=1500;
x43>=0;x43<=8;y43>=1200;y43<=2000;
x44>=0;x44<=3;y44>=1800;y44<=3500;
x51>=0;x51<=10;y51>=750;y51<=1750;
x52>=0;x52<=4;y52>=1000;y52<=1500;
x53>=0;x53<=8;y53>=1200;y53<=2000;
x54>=0;x54<=3;y54>=1800;y54<=3500;
@gin(x31);@gin(x32);@gin(x33);@gin(x34);
@gin(x41);@gin(x42);@gin(x43);@gin(x44);
@gin(x51);@gin(x52);@gin(x53);@gin(x54);
end

Answer 1

没错。。。。
结果为

Local optimal solution found.
Objective value: -4352940.
Extended solver steps: 55
Total solver iterations: 1655

（如果真报错估计是软件问题换一个，lingo10.0绝对可用，已破解。下载地址：http://maths.hqu.edu.cn/New/UploadFiles/lingo10.0.rar ）

追问

但是我怎么觉得应该是个正数呢？

追答

那你检测一下式子有没有写错了。。。。不是语法问题。。。。