I've gotten into a problem I haven't really worked with before in my numerics classes.
I have a system of four nonlinear equations with six parameters.
Newtons method, Boydens method etc. all include the inverse of the jacobian, but if the system is underdetermined this is not defined as far as I understand.
My only other generic idea is to reduce the number of parameters and then solve a system of four nonlinear equations with four parameters and iterate the last two, but this seems to get out of hand as well.
Is there any straightforward way to solve this kind of problems, or am I right in being a bit stuck?
Just consider two of the variables as free parameters and solve for the remaining four.
Unless there are other constraints, you get a double infinity of solutions.