How to force intlinprog to give integer solution ?

Jan
2015 11 7
2 个回答
更新时间：2015 11 9
2 次查看（30 天）

1 个投票

The following command
x=intlinprog([0; 0; 0],[1 2 3],-[0 2 0;0 1 2;3 1 0],-[6;13;11],[],[],[0;0;0],[])
produced x=[2.6667 3 5]' which is not integer.

请先登录，再回答此问题。

回答（2 个）

Matt J
Matt J 2015-11-7
编辑：Matt J 2015-11-7

0 个投票

I think it's a bug. If your goal is simply to find some feasible solution to the constraints, I think you can workaround the bug with any nonzero f vector, e.g.,
>> x=intlinprog([1e-10,0,0],[1 2 3],-[0 2 0;0 1 2;3 1 0],-[6;13;11],[],[],[0;0;0],[]);
x =
0
11
1

3 个评论
显示 1更早的评论 隐藏 1更早的评论

Jan
Jan 2015-11-7
编辑：Walter Roberson 2015-11-7
Thanks for the prompt answer, but try the following real optimization:
x=intlinprog([0; 1; 0],[1 2 3],-[0 2 0;0 1 2;3 1 0],-[6;13;11],[],[],[0;0;0],[]);
This gives x=[2.6667 3 5]'. Moreover, I have no idea how to find a proper f in a bigger problem.
Walter Roberson
Walter Roberson 2015-11-7
What is the exitflag being returned? You do not appear to be recording the exitflag so you do not know what the output represents.
Jan
Jan 2015-11-8
编辑：Walter Roberson 2015-11-8
Walter,
[x,y,exitflag,output]=intlinprog([0;1;0],[1 2 3],-[0 2 0;0 1 2;3 1 0],-[6;13;11],[],[],[0;0;0],[])
gives:
Optimal solution found.
Intlinprog stopped at the root node because the objective value is within a gap tolerance of the
optimal value, options.TolGapAbs = 0 (the default value). The intcon variables are
integer within tolerance, options.TolInteger = 1e-05 (the default value).
x =
2.6667
3.0000
5.0000
y =
3
exitflag =
1
output =
relativegap: 0
absolutegap: 0
numfeaspoints: 1
numnodes: 0
constrviolation: 0
message: 'Optimal solution found.…'

请先登录，再进行评论。

Alan Weiss
Alan Weiss 2015-11-9
编辑：Alan Weiss 2015-11-9

0 个投票

I think that this must be a bug in your Optimization Toolbox™ version. Please report the issue to technical support. There might be a workaround.
Alan Weiss
MATLAB mathematical toolbox documentation

类别

在 帮助中心 和 File Exchange 中查找有关 Linear Programming and Mixed-Integer Linear Programming 的更多信息

产品

标签

提问:

Jan
Jan
2015-11-7

编辑：

Alan Weiss
Alan Weiss
2015-11-9

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by