HELP:) Electric Field lines on MatLab (solving fields given coordinate points)

Currently I have used and edited a code that I have found on creating electric field lines on MatLab, I have use two test points at set coordinates with set charges [1 -1], yet the field lines that I get on my solution is incorrect. The direction of the lines should be all away from positive and towards the negative charges. Please help me fix this code!

x=[3 8];
y=[5 5];
q=[-1 1];

% Coulumb's number
ke = 8.9875517873681764e9;

xi=linspace(0,10,33);
yi=linspace(0,10,33);
[XI YI] = meshgrid(xi,yi);

zi = complex(XI,YI);
z = complex(x,y);
[ZI Z]=ndgrid(zi(:),z(:));

dZ = ZI-Z;
Zn = abs(dZ);

E = (dZ./Zn.^3)*(q(:)*ke);
E = reshape(E,size(XI));

En = abs(E);
Ex = real(E);
Ey = imag(E);

figure;
quiver(XI,YI,Ex./E,Ey./E);

hold on;
plot(x,y,'or');
axis equal;

Thank you,

[Erina Joyee]

correction:

figure; quiver(XI,YI,Ex./En,Ey./En);

[Rik]

Why did you remove your question content? Now it has become utterly useles. Even old questions can be very useful if they happen to solve the exact problem you're having.

[Rena Berman]

(Answers Dev) Restored edit

Answer 1

[Matt]

In your line quiver(XI,YI,Ex./E,Ey./E); change E to En.

You are currently dividing by a complex number.

Answer 2

[Antonio Cedillo Hernandez]

Here you have the full MATLAB code explained (in spanish but the first comment is the code): https://www.youtube.com/watch?v=k9srU6aQfL0