constrained optimization and supports linear and nonlinear constraints. X =, constraint is g(x)-f(x)-1 (x-c)^4 -0.1(x-5)^2 -0.1(x-5)^2 (x-c)^4 -0.1(x-5)^2 -0. 1.6K 215K views 5 years ago Computational Tools for Engineers This step-by-step tutorial demonstrates fmincon solver on a nonlinear optimization problem with one equality and one inequality. fmincon is a Nonlinear Programming solver provided in MATLABs Optimization Toolbox. When the following nonlinear constraint is added, fmincon gives the wrong result (x (1) 0, x (2) 0 and y 0) Any comments Thanks a lot - fun2. I updated your optimization function and the solution c is as follow the optimal solution is: x (1) 1, x (2) 2 and y 0 without nonlinear constraint, the result is correct. The function ceq (x) represents the constraint ceq (x) 0. A nonlinear constraint function has the syntax c,ceq nonlinconstr (x) The function c (x) represents the constraint c (x) < 0. Another issue A = int(f,)-int(g,) = 55/6 - c^5/5 instead ofĪ = 2*(int(f,)-int(g,)) = 55/3 - (2*c^5)/5įactor 2 is used whether for even whether for odd function (like cosine or since).Įven for those kind of function the integration interval is reduced by half Include nonlinear constraints by writing a function that computes both equality and inequality constraint values. Technically you need to know the optimum c before solving 1. Your problem is more related to calculus than matlab toolĬ= are just ignored by fmincon, because they are not logical Deciding if a point is in a polygon is a yes/no decision. Does anyone know why this happens and why MATLAB does not respect the constraints when I put them up for the whole range ? 1 Answer Sorted by: 0 No, because that would introduce non-smoothness in your optimization problem. But when I delete the unneccessary constraints in the range ]2 5] function =cons_Q6(x) Now, when I solve it like this I get a solution that doesn't fit all the constraints. = constraints file looks like this (I inserted a lot of values for x with an increment of 0.1): function =cons_Q6(x)Īs you can see, I've set the bounds for the unknown variable so that x(1)= and I have set the constraints in the range although I would only need them in the range of because of the bounds for x(1). ![]() Minimize A=2*(int(f,)-int(g,))=55/3 - (2*c^5)/5Īlso I have the constraint that f(x) must always be 1 unit above the functions g(x) and h.įrom the graph I know that the variable c must be between 0 and 2 (just a range for the fmincon function). I want to minimize the Area between the function f(x) and the two connected functions g(x) and h, in the interval ![]() Our first constraint is x1 + x2 1, so well have to subtract 1 to form (x1 + x2 - 1) 0. I want to use MATLABs fmincon function to solve a non-linear problem of which I know that it can be solved in a different way very easily but I want to use fmincon (you might not need the following detailed information about the problem but I provided them in case you need):įunction f(x) is a quadratic function with its vertex at point (5|1).įunction g(x) is a polynom of order 4 with its vertex at Point (c|0). fmincon expects constraints of the form c < 0 and ceq 0.
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