function deltF=func_deltF(measurement,busNum,fsY11,Loadi,V1r,V1i,I1r,I1i)
% H=[
%     real(fsY11),-imag(fsY11),zeros(busNum,length(Loadi)*2);
%     imag(fsY11),real(fsY11),zeros(busNum,length(Loadi)*2);
%     zeros(length(Loadi),busNum*2), eye(length(Loadi)),zeros(length(Loadi));
%     zeros(length(Loadi),busNum*2), zeros(length(Loadi)),eye(length(Loadi));
% ];
% X=[V1r;V1i;I1r;I1i];
% deltF=-H'*(measurement-H*X);
deltF=[
    zeros(busNum*2,1);
    -2*( [real(measurement);imag(measurement)]-[I1r;I1i]);
];
% deltF=0;
end