Nonlinear equation system solver: broyden

Solve set of nonlinear equations. Optionally define bounds on independent variables.

This function tries to solve f(x) = 0, where f is a vector function. Uses Broyden's pseudo-Newton method, where an approximate Jacobian is updated at each iteration step, using no extra function evaluations. The optional bounds keep the search within a rectangular region.

fsolve from the optimisation toolbox is more robust but lacks the bounds option.