[V_HAT, LAM_HAT] = CPF_PREDICTOR(V, LAM, Z, STEP, PV, PQ)
Computes a prediction (approximation) to the next solution of the
continuation power flow using a normalized tangent predictor.
Inputs:
V : complex bus voltage vector at current solution
LAM : scalar lambda value at current solution
Z : normalized tangent prediction vector from previous step
STEP : continuation step length
PV : vector of indices of PV buses
PQ : vector of indices of PQ buses
Outputs:
V_HAT : predicted complex bus voltage vector
LAM_HAT : predicted lambda continuation parameter