Add a Control Variable Field specific to the geometric entity level (domain, edge, boundary, or point) in question.

The field can be accessed via its Control variable name throughout the model, and the Initial value can also be specified.

If desired, you can scale the control variable using a scalar value that you enter in the Scale field (default: 1; that is, no scaling). A large scale will generally cause the optimization solvers to take longer steps (MMA without move limits is the exception).

This section contains settings for the element used to discretize the control variable. Select a Shape function type: Lagrange (the default) or Discontinuous Lagrange. Also select an Element order: Linear, Quadratic (the default), Cubic, Quartic, Quintic, Sextic, or Septic. For Discontinuous Lagrange, one can also pick Constant shape functions. The value type (complex or real) for all the variables defined by this Global Equations node is selected in the Value type when using splitting of complex variables selection. The default value type is Complex.