matlab绘制三维电偶极子的电场和电势.zip

% % 三维电偶极子：本程序绘制三维电偶极子的电场和电势 % % written by Shan Jin % % modified on Mar 14, 2019 % % 程序中令e^2/(4*pi*epsilon_0)=1​ % 预设参数 q = 1; % 强度系数，以e^2/(4*pi*epsilon_0)为单位 R = 5; % 正负电荷之间的间距 pp = [0 -R/2 0];% 正电荷位置 pm = [0 R/2 0];% 负电荷位置​ % 计算电势 [X1,Y1,Z1] = meshgrid(-R:0.1:R); rp = sqrt( (X1-pp(1)).^2 + (Y1-pp(2)).^2 + (Z1-pp(3)).^2 ); % 到正电荷的距离 rm = sqrt( (X1-pm(1)).^2 + (Y1-pm(2)).^2 + (Z1-pm(3)).^2 ); % 到负电荷的距离 phi1 = q./rp - q./rm; % 电势 [X,Y,Z,phi] = subvolume(X1,Y1,Z1,phi1,[NaN NaN NaN NaN NaN 0]);% 只保留上半平面​ figure % --------------- 画等势面 ---------------- % phi_r = 1; % 等势面取值范围 for phi0 = -phi_r:phi_r/3:phi_r isosurface(X,Y,Z,phi,phi0) end colorbar axis([-R R -R R -R R]) % -------------- 画实体等势面 ------------ % isocaps(X,Y,Z,phi,phi_r/3) colormap(hsv) % 更换色彩显示​ % --------------- 画电场线 ---------------- % [Ex, Ey, Ez] = gradient(-phi1); [sx, sy, sz] = meshgrid(-R:R:R,-R,0:R/2:R); [sx0, sy0, sz0] = meshgrid(-R:R:R,0,0:R/2:R); El1 = streamline(X1,Y1,Z1,-Ex,-Ey,-Ez,sx,sy,sz);% 电场线 El2 = streamline(X1,Y1,Z1,Ex,Ey,Ez,sx,-sy,sz); El3 = streamline(X1,Y1,Z1,-Ex,-Ey,-Ez,sx0,sy0,sz0); El4 = streamline(X1,Y1,Z1,Ex,Ey,Ez,sx0,sy0,sz0); set(El1,'LineWidth',1,'Color','k') set(El2,'LineWidth',1,'Color','k') set(El3,'LineWidth',1,'Color','k') set(El4,'LineWidth',1,'Color','k') view(-70,40) % 调整视角 % ------------------------------------------- % title('三维偶极子的电场和电势')