Linear constraints using lsqnonlin
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Hi, I'm solving a non-linear system of 3 equations in 3 unkowns:
I'm using lsqnonlin to solve it:
lambda = lsqnonlin(F,lambda0,lb,ub,options);
Moreover, I need to add some constraints to the variables:
How can pass this constraints to the solver?
Thanks in advance!
2 Comments
Walter Roberson
on 28 Sep 2022
A system of 3 equations in 3 unknowns usually as a unique solution.
That is not generally the case for nonlinear systems. For example 3 curved surfaces might intersect at multiple locations and the constraints could narrow the result down to one particular quandrant.
Accepted Answer
Walter Roberson
on 28 Sep 2022
lsqnonlin() does not support constraints other than upper bound and lower bound.
I suggest you minimize the norm() of F(x,y,z)-lambda0 using fmincon() as you can supply linear inequality constraints for that.
2 Comments
Matt J
on 30 Sep 2022
Or rather minimize norm( F(x,y,z) )^2 to ensure differentiability of the objective.
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