hold on
axis equal

for x=-2:0.1:2
    for z=-2:0.1:2
   
    r=sqrt(power(x,2)+power(z,2));
    if (r >1 && r<2)
    [bx,by,bz]=magf(x,0,z);
    quiver(x,z,bx,bz,0.1);
   end
end
end   
phi=0:5:360;
xk=cosd(phi);yk=sind(phi);
plot (xk,yk);
%axis([-2,2,-2,2])
%xlabel('x');ylabel('z');
