function ddg=func_ddg(busNum,Loadi,Init_Z,Init_W)

Init_ZW=Init_Z+Init_W;
t=[2*diag( ones(length(Loadi),1).*Init_ZW),zeros(length(Loadi));
    zeros(length(Loadi)),2*diag( ones(length(Loadi),1).*Init_ZW);
];
ddg=[
    zeros(busNum*2,busNum*2+length(Loadi)*2);
    zeros(length(Loadi)*2,busNum*2), t;
];
end