The Jacobian Panel

The Pisces Jacobian Panel.

The top of the Jacobian panel contains fields that determine how Pisces computes finite-difference derivatives.

The remainder of the panel determines stopping criteria for Newton's methods of finding roots.

epsi_func

If the norm of the model evaluated at a point x is less than the value of this field, then x is determined to be a zero of the model.

epsi_vars

During Newton's method, if the size of the Newton step distance is less than the value of this field, then we stop Newton's method because we are either not converging to a root or are converging very slowly.

newt_step

The value of this field determines the number of Newton steps we are allowed to take before deciding that an initial guess will never converge to a root.