%this code runds perfectly on octave
clear all;

rho = 10;
I=100;
d=10;
C=0;

%optinal 
re=0.01; %[m]
%
%Calculations
%

%the grid
[X,Y,Z]=meshgrid(-7:0.5:7,-7:0.5:7,-7:0.5:0);

%distances
r1=sqrt((X-d/2).^2+Y.^2+Z.^2); %[m]
r2=sqrt((X+d/2).^2+Y.^2+Z.^2); %[m]

%avoid devision by zero
r1(r1<re)=re;
r2(r2<re)=re;
%electrical potential 
phi=I./(2*pi*r1)*rho-I./(2*pi*r2)*rho+C; %[V]

%%%
%3-D plotting
%%%

%slices
figure(1)
clf
slice(X,Y,Z,phi, [-d/2 0 d/2],[0],[-7 -3.5 0])
%markersize(0.5)
%markersize(0.5)
shading interp;
colorbar
caxis([-100 100])
box on
xlim([-7 7])
ylim([-7 7])
zlim([-7 0])
title('Slices of electrical potential')
xlabel('X [m]')
ylabel('Y [m]')
zlabel('Z [m]')