2017-04-17 68 views
2

我想复制我在Matlab中的研究论文中找到的线性优化。我需要解决以下线性优化问题:MatLab中求和的线性规划

objective function

其中C1C2C3C4C5W1W2是优先权重。

j取自1至12(一年的12个月)。

以下限制适用:

constraint functions

I(j)的和L(j)是按月记录。

我使用MatLab来编写解决方案。这里是我的代码(我很新的这一点,所以请原谅任何不好的编码!):

%set up the data for the year: 
I = [72.6 26.0 23.2 20.4 15.2 22.0 40.9 45.2 38.7 41.4 142.2 116.8] 
L = [1.6 1.3 0.8 0.6 0.6 0.6 1 1.5 1.8 1.8 1.8 2.0]; 
%set up the initial level: 
S0 = 683 
%set up the priority weightings 
w2= 1; 
w1 = 1.5; 
C1 = 3; 
C2 = 2; 
C3 = 5; 
C4 = 4; 
C5 = -5; 
%set up the constraint equation, lower bond and upper bound 
A = [(C1*w1) C2 (C3*w2) (C4*w2) C5]; 
Aeq = [1 1 1 1 1]; 
lb = [70 0 0 0 0]; 
ub = [815 54.14 13.4 41.8 17345]; 
%set up a blank matrix to store the results 
x=zeros(12,5); 

%for each month calculate the optimum and store in the matrix 
for j = 1:12 
    Beq = [(I(j)+S0-L(j))]; 
    x(j,:) = linprog(-A,[],[],Aeq,Beq,lb,ub); 
    S0 = x(j,1); 
end 

%output the result 
opt = x 

问题是,当我比较我的结果的研究论文中,我发现,我得到不同的结果。最终我意识到我正在为每个月找到最佳状态,而不是全年的全球最佳状态。我一直在网上搜索如何找到全年的最佳值(即优化求和函数),但我找不到任何东西。任何人都可以将我指向正确的方向吗?

+0

有一个在Matlab的linprog没有总和。它完全基于矩阵。对于某些问题,这是没有问题的,对于其他问题,这是噩梦(参见[这里](http://yetanothermathprogrammingconsultant.blogspot.com/2016/10/matlab-vs-gams-integer-programming.html))。在你的情况下,你需要建立一个大矩阵,每一列对应一个变量,每一行对应一个约束。 –

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@ErwinKalvelagen非常感谢您的回复。我用你的例子来解决我的问题。 –

回答

0

感谢@ErwinKalvelagen我能解决我的问题。这里是未来的我为别人解决方案:

%set up the data for the year: 
I = [72.6; 26.0; 23.2; 20.4; 15.2; 22.0; 40.9; 45.2; 38.7; 41.4; 142.2; 116.8;]; 
I = I*1; %allows the inflow to be scaled to test the model for a dry or wet year 
L = [1.6; 1.3; 0.8; 0.6; 0.6; 0.6; 1; 1.5; 1.8; 1.8; 1.8; 2.0;]; 

%set up the priority weightings 
w1 = 2; 
w2= 50; 
C1 = 3; 
C2 = 2; 
C3 = 5; 
C4 = 4; 
C5 = -5; 

%set up the constraint equation, lower bond and upper bound 
A = [(C1*w1) C2 (C3*w2) (C4*w2) C5 (C1*w1) C2 (C3*w2) (C4*w2) C5 (C1*w1) C2 (C3*w2) (C4*w2) C5 (C1*w1) C2 (C3*w2) (C4*w2) C5 (C1*w1) C2 (C3*w2) (C4*w2) C5 (C1*w1) C2 (C3*w2) (C4*w2) C5 (C1*w1) C2 (C3*w2) (C4*w2) C5 (C1*w1) C2 (C3*w2) (C4*w2) C5 (C1*w1) C2 (C3*w2) (C4*w2) C5 (C1*w1) C2 (C3*w2) (C4*w2) C5 (C1*w1) C2 (C3*w2) (C4*w2) C5 (C1*w1) C2 (C3*w2) (C4*w2) C5]; 

%set up spare matrix for Aeq 
Aeq = zeros(12,60); 

% Populate Aeq 
% first the positive portions of the monthly data 
row = 1; 
coloumn = 1; 
for counter = 1:12 
    for counter = 1:5 
     Aeq(coloumn,row)=1; 
     row = row + 1; 
    end 
    coloumn = coloumn+1; 
end 
% then the -S0 for each month 
Aeq(1, 56)=-1; 
coloumn = 1; 
for row = 2:12 
    Aeq(row,coloumn)=-1; 
    coloumn = coloumn+5; 
end 

%populate Beq 
Beq = I-L; 

%populate the lower and upper bounds 
Smin = 70; 
Smax_1_9 = 731.2; 
Smax_10_12 = 673.2 
QDmin = 0 
QDmax = 54.14 
Rmin = 0; 
Rmax = 13.4; 
RRmin = 0; 
RRmax = 41.8; 
SPILLmin = 0; 
SPILLmax = 17345; 
%first the lower bound 
lbmonthly = [Smin; QDmin; Rmin; RRmin; SPILLmin;]; 
lb = vertcat(lbmonthly,lbmonthly,lbmonthly,lbmonthly,lbmonthly,lbmonthly,lbmonthly,lbmonthly,lbmonthly,lbmonthly,lbmonthly,lbmonthly); 
%second the upper bound 
ubmonthly_1_9 = [Smax_1_9; QDmax; Rmax; RRmax; SPILLmax;]; 
ubmonthly_10_12 = [Smax_10_12; QDmax; Rmax; RRmax; SPILLmax;]; 
ub = vertcat(ubmonthly_1_9, ubmonthly_1_9, ubmonthly_1_9, ubmonthly_1_9, ubmonthly_1_9, ubmonthly_1_9, ubmonthly_1_9, ubmonthly_1_9, ubmonthly_1_9, ubmonthly_10_12, ubmonthly_10_12, ubmonthly_10_12); 

%find the optimal 
opt = linprog(-A,[],[],Aeq,Beq,lb,ub); 

%output the result as a matrix 
opt = reshape(opt,5,12)'