西电电院电磁场与电磁波大作业

q=-2/5;xm=4;ym=4;x=linspace-xmxm;y=linspace-ymym;[XY]=meshgridxy;R1=sqrtX+

1.^2+Y.^2;R2=sqrtX-

1.^2+Y.^2;U=5*

1./R1+q./R2;u=-5:

0.3:5;figurecontourXYUugridonlegendnum2struholdonplot[-xm;xm][0;0]plot[0;0][-ym;ym]plot-10oMarkerSize12plot10oMarkerSize12[ExEy]=gradient-Ux2-x1y2-y1;dangle1=20;angle1=dangle1:dangle1:180-dangle1*pi/180;r0=

0.1;x1=r0*cosangle1-1;y1=r0*sinangle1;streamlineXYExEyx1y1streamlineX-YEx-Eyx1-y1dangle2=dangle1/q;angle2=180-dangle2:-dangle2:dangle2*pi/180;x2=r0*cosangle2+1;y2=r0*sinangle2;streamlineXYExEyx2y2streamlineX-YEx-Eyx2-y2axisequaltighttitle+5电荷和-2电荷的电场线和电位线fontsize20xlabel\itxfontsize16ylabel\ityfontsize16text-xmym-

0.5电势单位:\itkQ\rm_1fontsize16txt=[电荷比:\itQ\rm_2/\itQ\rm_1=num2strq];text-xm-ym+

0.5txtfontsize16z=0:

0.03:5;Ex=2*cosz*2*pi;Ey=2*cosz+1/4*2*pi;figure1plot3ExzEyblinewidth2;gridonholdonplot3[-2;2][0;0][0;0];plot3[0;0][0;5][0;0];plot3[0;0][0;0][-2;2];axis[-2205-22]xlabelx轴;ylabelz轴;zlabely轴;title螺旋线。