Add constraints to intermediate variables in the process of using least squares to minimize the objective function to fit the parameters of the equation

To fit the equation parameters using the least squares method, constraints need to be added to the variables during the calculation

How can I add these constraints to my function file, or create a new function file for these constraints?

Answer 1

[Matt J]

With the constraints you mention, the problem does not fall within the scope of lsqnonlin. You will have to use fmincon, which allows you to implement any differentiable nonlinear constraints you wish.

Note however that imposing nonlinear constraints will not narrow or simplify the search for the solution, if that's what you were hoping. They will just (potentially) improve the conditioning of the result.