function deltF=func_deltF(PG,QG,PVi,PGi,wPG,wQG,wPD,wQD,PG0,QG0,PD0,PD,QD,QD0,Busnum,Loadi)
t3=2*wPD.*(PD(Loadi)-PD0(Loadi));
t4=2*wQD.*(QD(Loadi)-QD0(Loadi));
deltF=[sparse(length(Loadi),1);
sparse(length(Loadi),1);
sparse(2*Busnum,1);
sparse(ones(Busnum,1));
];
end