MATLAB Answers

## Multiple linear equality constraints in fmincon

Asked by sharadhi

### sharadhi (view profile)

on 4 Apr 2019
Latest activity Edited by sharadhi

### sharadhi (view profile)

on 4 Apr 2019
Accepted Answer by Torsten

### Torsten (view profile)

Hi
I am optimising the elements of a matrix X based on an ojbective function. I know what value of sum of row elements and sum of column elements should be. I want to optimize the matrix based on these 2 constraints.
If the size of the matrix is , for row and column,
1) sum of column 1 elements: = known column 1 sum.
This can be done for every column giving n column constraints.
I can represent this in where =ones(1,n) and = known vector
2) I need to do the same for row elements too. I have the known vector.
I'm unable to define one and which constraints the row sum as well as column sum of matrix X
Thank you

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## 1 Answer

Answer by Torsten

### Torsten (view profile)

on 4 Apr 2019
Accepted Answer

Aeq = [1 0 1 0 ; 0 1 0 1 ; 1 1 0 0 ; 0 0 1 1];
beq = [sum of column 1 ; sum of column 2 ; sum of row 1 ; sum of row 2]
X = [X11 ; X12 ; X21 ; X22]
This is the configuration for n=2. Can you take it from here ?

sharadhi

### sharadhi (view profile)

on 4 Apr 2019
Yes. That was something I didn't think of. Thanks Torsten

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