Optimization Toolbox

Additional Arguments: Avoiding Global Variables

You can pass parameters that would otherwise have to be declared as global directly to M-file functions using additional arguments at the end of the calling sequence.

For example, entering a number of variables at the end of the call to fsolve

• [x,fval] = fsolve(@objfun,x0,options,P1,P2,...)
  

passes the arguments directly to the function objfun when it is called from inside fsolve:

• F = objfun(x,P1,P2, ... )
  

Consider, for example, finding zeros of the function ellipj(u,m). The function needs parameter m as well as input u. To look for a zero near u = 3, for m = 0.5,

• m = 0.5;
  options = optimset('Display','off'); % Turn off Display
  x = fsolve(@ellipj,3,options,m)
  

returns

• x = 
      3.7081
  

Then, solve for the function ellipj:

• f = ellipj(x,m)
  f =
      -2.9925e-008
  

The call to optimset to get the default options for fsolve implies that default tolerances are used and that analytic gradients are not provided.

Maximization

Nonlinear Equations with Analytic Jacobian