code-dump/VectorField.m at main · cipryyyy/code-dump · GitHub

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clc, clearvars, close all

l = -1.5; r = 1.5; d = 0.2;

[x,y,z] = meshgrid(l:d:r, l:d:r, l:d:r);

c1x = -0.6; c1y = 0; c1z = 0; q1 = 1e-8;
c2x = 0.6; c2y = 0; c2z = 0; q2 = -1e-8;

k = 1/(4*pi*8.85e-12);

r1x = x - c1x;
r1y = y - c1y;
r1z = z - c1z;
r1 = sqrt(r1x.^2 + r1y.^2 + r1z.^2);

r2x = x - c2x;
r2y = y - c2y;
r2z = z - c2z;
r2 = sqrt(r2x.^2 + r2y.^2 + r2z.^2);

E1x = k * q1 * (r1x./r1.^3);
E1y = k * q1 * (r1y./r1.^3);
E1z = k * q1 * (r1z./r1.^3);

E2x = k * q2 * (r2x./r2.^3);
E2y = k * q2 * (r2y./r2.^3);
E2z = k * q2 * (r2z./r2.^3);

u = E1x + E2x;
v = E1y + E2y;
w = E1z + E2z;

figure(1)
title("Electric field")
subtitle("Graph of a field generated by two opposite charges")
hold on

minR = 0.1;
mask = (r1>minR) & (r2>minR);

xq = x(mask);
yq = y(mask);
zq = z(mask);
uq = u(mask);
vq = v(mask);
wq = w(mask);

quiver3(xq,yq,zq,uq,vq,wq,5);
plot3(c1x, c1y, c1z, "ob", 'MarkerSize', 10, 'MarkerFaceColor', "blue")
plot3(c2x, c2y, c2z, "or", 'MarkerSize', 10, 'MarkerFaceColor', "red")
view(3)

[startX, startY, startZ] = meshgrid(-0.8:0.25:-0.4, -1:0.25:1, -1:0.25:1);

verts = stream3(x,y,z,u,v,w,startX,startY,startZ);
streamline(verts, "Color", "yellow");

xlim([-1 1]), ylim([-1 1]), zlim([-1 1])
xlabel("x"),ylabel("y"),zlabel("z")

az = 0;
while true
    az = mod(az+1,360);
    view(az, 30);  % azimuth changes, elevation fixed
    drawnow;
    pause(0.01)
end