clear all
clc

z=0;
L=1;

[x, y]=meshgrid(-0.5 : 0.01 : 0.5,-0.5 : 0.01: 0.5);
V= log((z+L+sqrt(x.^2+u.^2+(z+ L)^2))./(z-L+sqrt(x.^2+y.^2+(z-L)^2)));
[FX, FY] = gradient(V,0.1,0.1)
contour(x, y, V), hold off, quiver(x,y,FX, FX), hold on


여기서 x,y 그래디언트를 그래프로 나타내고 싶은데
점만 나와 이 좆뉴비가 뭘 잘못한거임