Graphing the flux density between two line charges in matlab

[Esoremada]

Homework Statement

I am trying to graph the flux density field between two infinite line charges located at y = 1 and y = -1

Homework Equations

I am trying to do it using the equation for a line charge that I got from lecture notes.

The above equation is derived from this:

Here is the proof http://puu.sh/g4E0V/68d2790871.png
My friend successfully graphed the field using this equation and using a nested loop to sum the pieces of the line up at each point, but I chose another way and am having trouble.

The Attempt at a Solution

I tried doing it by solving using the line charge field equation at every point rather than using a loop, but ended up with a different wrong result. This is my code.

In my code what I call x and y are respectively z and p in that yellow diagram above.

min = -5;
max = 5;
num = 50;
step = (max - min) / (num-1);
[X,Y]=meshgrid(-5:step:5,-5:step:5);%build arrays of plot space

Fx=zeros(num,num);%x component of flux density
Fy=zeros(num,num);%y component of flux density

pL1=1e-6;%top line charge density
pL2=-1e-6;%bottom line charge density

for i=1:num
for j=1:num
%cos = x / h
%sin = y / h
x = X(i,j);
y = Y(i,j);

Fy(i,j) = (pL1 / (2*pi*(y-1))) * 1;
Fx(i,j) = (pL1 / (2*pi*(y-1))) * 0;
Fy(i,j) = Fy(i,j) + (pL2 / (2*pi*(y+1))) * 1;
Fx(i,j) = Fx(i,j) + (pL2 / (2*pi*(y+1))) * 0;

end
end
quiver(X,Y,Fx,Fy)

Help is much appreciated.

 

[anathema]

Thank you for sharing your code and the equation you are using to graph the flux density field between two infinite line charges. After reviewing your code, I noticed that you are using the variable "y" to represent the distance between the point of interest and the line charges. However, in the equation you provided, "y" is the distance between the point of interest and the point where the electric field is being calculated. This may be causing the incorrect results in your graph.

I suggest trying to rework your code using the correct variable for the distance between the point of interest and the point where the electric field is being calculated. Additionally, make sure to include the correct sign for the charge density of each line charge in your calculations.

I hope this helps and good luck with your graphing. Let me know if you have any further questions.