function [Pg,Qg,Vm,DVm,z,z11,z22,z33,z44,Plossreal,Qlossreal,dQQg]=auto(busdata,linedata)
basemva = 100;  accuracy = 0.001; accel = 1.8; maxiter = 100;
ybus                            % form the bus admittance matrix
newton              % Load flow solution by Gauss-Seidel method