Learning Forum

[chenymjxzs]

######## y-z plane (phi=0 corresponds to the direction (0,1,0))
    ?"    Projecting in y-z plane";
    x = 0; y = cos(phi*pi/180);  z = sin(phi*pi/180);

    # Calculate far field by summing contribution from each monitor
    temp = farfieldexact("x2",x,y,z,i) + farfieldexact("y2",x,y,z,i) + farfieldexact("z2",x,y,z,i);
    if(havedata("x1")){
      temp = temp - farfieldexact("x1",x,y,z,i);
    }else{
      temp2 = farfieldexact("x2",-x,y,z,i);
      s = symm_x*[1,-1,-1];
      temp2(1:npts,1) = s(1)*temp2(1:npts,1);
      temp2(1:npts,2) = s(2)*temp2(1:npts,2);
      temp2(1:npts,3) = s(3)*temp2(1:npts,3);
      temp = temp - temp2;
    }
    if(havedata("y1")){
      temp = temp - farfieldexact("y1",x,y,z,i);
    }else{
      temp2 = farfieldexact("y2",x,-y,z,i);
      s = symm_y*[-1,1,-1];      
      temp2(1:npts,1) = s(1)*temp2(1:npts,1);
      temp2(1:npts,2) = s(2)*temp2(1:npts,2);
      temp2(1:npts,3) = s(3)*temp2(1:npts,3);
      temp = temp - temp2;
    }
    if(havedata("z1")){
      temp = temp - farfieldexact("z1",x,y,z,i);
    }else{
      temp2 = farfieldexact("z2",x,y,-z,i);
      s = symm_z*[-1,-1,1];
      temp2(1:npts,1) = s(1)*temp2(1:npts,1);
      temp2(1:npts,2) = s(2)*temp2(1:npts,2);
      temp2(1:npts,3) = s(3)*temp2(1:npts,3);
      temp = temp - temp2;
    }
    E_yz (1:length(phi), 1:3, i) = temp;
    E2_yz (1:length(phi), i) = sum(abs(temp)^2,2); # E2 = |Ex|^2 + |Ey|^2 + |Ez|^2
    H2_yz (1:length(phi), i) = E2_yz (1:length(phi), i) * n^2 * eps0/mu0; # for a plane wave, E^2 and H^2 only differ by a factor of n^2*eps0/mu0
首先我不能理解为什呢计算远场需要全部加起来：也就是：temp = farfieldexact("x2",x,y,z,i) + farfieldexact("y2",x,y,z,i) + farfieldexact("z2",x,y,z,i);

其次，我不知道为什么加起来之后又需要这么处理

if(havedata("x1")){ temp = temp - farfieldexact("x1",x,y,z,i); } else { temp2 = farfieldexact("x2",-x,y,z,i); s = symm_x*[1,-1,-1]; temp2(1:npts,1) = s(1)*temp2(1:npts,1); temp2(1:npts,2) = s(2)*temp2(1:npts,2); temp2(1:npts,3) = s(3)*temp2(1:npts,3); temp = temp - temp2; }