There is a error in my code. I have attached the equaion and my code. Kindly correct the part where i went wrong.

CODE:

r1=sqrt((x+a1).^2+(y+a2).^2+(z.^2)) %a1,a2,x,y and z are defined

r2=sqrt((a1-x).^2+(y+a2).^2+(z.^2))

r3=sqrt((a1-x).^2+(y-a2).^2+(z.^2))

r4=sqrt((x+a1).^2+(y-a2).^2+(z.^2))

C4=-a1-x

C1=-C4

C3=-a1+x

C2=-C3

d1=y+a2

d2=d1

d3=y-a2

d4=d3

I=2

for i=1:1:4

B=(((-1)^i*d(i))/(r(i)*(r(i)+((-1)^(i+1)*C(i)))))-(C(i)/(r(i)*(r(i)+d(i))))

Bz=((u*I)/(4*pi))*B

end

plot(z,Bz)

ERROR:

Undefined function or variable 'C'.

Answer 1

[Mark Sherstan]

You never defined a "C" variable. You have C1, C2, etc... but not just "C". Additionally, you need to perform a summation in the loop (you are currently just redefining B each time) so you should adjust the end of your code as such:

...
    
B = 0;
for i=1:1:4
    B = (((-1)^i*d(i))/(r(i)*(r(i)+((-1)^(i+1)*C(i)))))-(C(i)/(r(i)*(r(i)+d(i))))
    B = B + B;
end
Bz=((u*I)/(4*pi))*B
plot(z,Bz)