close all
clear
clc
x=linspace(-4,4,200);
y=x;
[X, Y]=meshgrid(x,y);
V=1./sqrt((X-1).^2+(Y).^2+eps)-1./sqrt((X+1).^2+Y.^2+eps);
[Ex, Ey]=gradient(V);
[C, K]=contour(X,Y,V,[-2:0.1:2]);
set(K,'levelstep',30);
[C1, h]=contour(X,Y,sqrt(Ex.^2+Ey.^2),[0:0.01:0.5]);
In the set command it shall be 'K' (capital), you typed 'k' (small case)
Best Answer