Optimisation of function containing matrix

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Isabelle Steinmann
Isabelle Steinmann el 10 de Oct. de 2019
Comentada: Isabelle Steinmann el 11 de Oct. de 2019
I am having trouble optimising this system. I have been trying to use fmincon without success.
C is a 16x16 matrix, mo and v and 1 are 16x1 vectors. I want to choose mo to maximise x = c*mo+v
The constraints are: the components of mo must add to one (I think I've done this one)
and each component of x should be equal, that is x1=x2=...=x16 where x=c*mo+v (I have no idea how to represent this)
fun = @(mo) -C*mo-v;
A=[];
b=[];
Aeq= ones(1,16);
beq= 1;
lb = zeros(16,1);
ub = ones(16,1);
m0 = 1/16*ones(16,1);
mo = fmincon(fun,m0,A,b,Aeq,beq,lb,ub)
Please let me know where I'm going wrong...
  3 comentarios
Isabelle Steinmann
Isabelle Steinmann el 10 de Oct. de 2019
C =
Columns 1 through 10
1.0003 0.0245 0.0052 0.0172 0.0273 0.0220 0.0171 0.0208 0.0073 0.0218
0.0054 0.9994 0.0100 0.0326 0.0329 0.0369 0.0173 0.0155 0.0224 0.0269
0.0152 0.0097 1.0001 0.0173 0.0374 0.0220 0.0222 0.0208 0.0174 0.0219
0.0001 -0.0000 0.0000 1.0005 0.0255 0.0054 0.0103 0.0101 0.0007 0.0057
0.0001 -0.0000 0.0000 0.0056 1.0006 0.0103 0.0052 0.0050 0.0055 0.0204
0.0001 -0.0003 -0.0000 0.0059 0.0108 1.0007 0.0009 -0.0097 0.0156 0.0054
0.0001 -0.0001 -0.0000 0.0112 0.0110 0.0255 1.0005 0.0001 0.0359 0.0105
0.0001 -0.0001 -0.0000 0.0112 0.0110 -0.0041 0.0257 1.0004 0.0262 0.0156
0.0000 -0.0003 -0.0000 0.0205 0.0008 0.0005 0.0005 0.0002 1.0005 0.0003
0.0001 -0.0001 -0.0000 0.0157 0.0011 0.0105 0.0056 0.0053 0.0108 1.0004
0.0001 -0.0002 -0.0000 0.0111 0.0210 0.0157 0.0162 0.0152 0.0213 0.0009
0.0000 -0.0003 -0.0000 0.0107 0.0154 0.0007 0.0150 -0.0000 0.0155 0.0054
0.0050 -0.0104 -0.0001 0.0213 0.0212 0.0164 0.0456 0.0151 0.0169 0.0159
-0.0001 -0.0200 -0.0001 0.0095 -0.0004 0.0092 -0.0102 -0.0052 -0.0006 0.0047
0.0000 -0.0101 -0.0001 0.0102 0.0054 0.0151 0.0006 -0.0099 0.0002 0.0001
0.0100 -0.0000 0.0000 0.0158 0.0309 0.0058 0.0007 0.0005 0.0057 0.0158
Columns 11 through 16
0.0213 0.0179 0.0317 0.0165 0.0165 0.0064
0.0068 0.0479 0.0367 0.0270 0.0316 0.0213
0.0216 0.0228 0.0316 0.0167 0.0164 0.0163
0.0005 0.0055 0.0002 0.0003 0.0002 0.0155
0.0007 0.0007 0.0003 0.0003 0.0002 0.0203
0.0152 0.0307 0.0204 0.0109 0.0107 0.0002
0.0158 0.0264 0.0008 0.0110 0.0007 0.0104
0.0158 0.0212 0.0054 0.0009 0.0055 0.0106
0.0149 0.0205 0.0053 0.0203 0.0053 0.0002
0.0205 0.0060 0.0056 0.0005 0.0054 0.0152
1.0009 0.0214 0.0204 0.0010 0.0058 0.0006
0.0002 1.0008 0.0004 0.0153 0.0200 0.0005
0.0159 0.0169 1.0008 0.0257 0.0202 0.0009
-0.0150 0.0041 0.0043 0.9998 -0.0103 -0.0002
0.0002 0.0151 0.0199 0.0004 1.0003 -0.0000
0.0154 0.0108 0.0057 0.0104 0.0054 1.0008
v is a zero vector
Fabio Freschi
Fabio Freschi el 11 de Oct. de 2019
It is better to attach data as mat file

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Respuesta aceptada

Fabio Freschi
Fabio Freschi el 10 de Oct. de 2019
Editada: Fabio Freschi el 11 de Oct. de 2019
While waiting for the data, I try to solve one of the questions. you can set the missing constraint as
x1-x2 = 0
x2-x3 = 0
...
so, let's call M the matrix with +1 -1 along the diagonal
M = diag(ones(16,1),0)+diag(-ones(15,1),1);
The last row has to be removed
% remove last row
M = M(1:end-1,:);
now, x = C*mo+v and we want M*x = 0, so Mx = M*C*mo+M*v = 0 and the new equality constraint is
% new constraints
Aeq2 = M*C;
beq2 = -M*v;
% append
Aeq = [Aeq; Aeq2];
beq = [beq; beq2];
However, the main problem is that your objective function returns a vector and not a scalar quantity. I don't know your problem but is the sum of all x a feasible objective function to maximize?
fun = @(mo) -sum(C*mo+v);
In this case the solution is
>> mo
mo =
0.0549
0.0481
0.0524
0.0668
0.0672
0.0644
0.0615
0.0627
0.0661
0.0655
0.0623
0.0653
0.0570
0.0737
0.0689
0.0633
>> sum(mo)
ans =
1
>> C*mo
ans =
0.0720
0.0720
0.0720
0.0720
0.0720
0.0720
0.0720
0.0720
0.0720
0.0720
0.0720
0.0720
0.0720
0.0720
0.0720
0.0720
  4 comentarios
Fabio Freschi
Fabio Freschi el 11 de Oct. de 2019
Isabelle, is it what you want?
Isabelle Steinmann
Isabelle Steinmann el 11 de Oct. de 2019
Yes, that's perfect. Thank you

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