2直線偏波による円偏波放射条件のアニメーション

2001/6/28 平野拓一

<< Algebra`ReIm`;
<< Graphics`Arrow`;

x2 = {1, 0};      
y2 = {Cos[θ], Sin[θ]};      
A = 
        ra Exp[I θa];
B = 
        rb Exp[I θb];
e = 
      A*x2 + B*y2  //  ComplexExpand

θ /: Im[θ] = 
          0;
ra /: Im[ra] = 
        0;
rb /: Im[rb] = 
        0;
θa /: Im[θa] = 
        0;
θb /: Im[θb] = 
        0;
ex = Re[e][[1]] + 
          I*Im[e][[1]];
ey = Re[
              e][[2]] + I*Im[e][[2]];

アニメーション

θ = 90  °;
ra = 1;
rb = 0.5;
θa = 0  °;
θb = θ + 180  °;
envelope = 
        ParametricPlot[
          Evaluate[(ra*x2*Cos[t + θa] + 
                rb*y2*Cos[t + θb])], {t, 0, 
            2 π}, 
AspectRatio -> 
            Automatic, 
DisplayFunction -> 
            Identity];
Table[
      Show[envelope, 
Graphics[{Arrow[{0, 
                0}, (ra*x2*Cos[t + θa] + 
                  rb*y2*Cos[t + θb])], 
{RGBColor[
                1, 0, 0], 
              Arrow[{0, 0}, 
                ra*x2*Cos[t + θa]]}, 
{RGBColor[0, 
                1, 0], Arrow[{0, 0}, 
                rb*y2*Cos[
                    t + θb]]}, 
{Dashing[{0.02, 
                  0.02}], 
              Line[{rb*y2*
                    Cos[t + θb], (ra*x2*Cos[t + θa] + 
                      rb*y2*Cos[
                          t + θb])}]}, 
{Dashing[{0.02, 0.02}], 
              Line[{ra*x2*
                    Cos[t + θa], (ra*x2*Cos[t + θa] + 
                      rb*y2*Cos[
                          t + θb])}]}
}], 
AspectRatio -> 
          Automatic, 
PlotRange -> {{-1, 
              1}, {-1, 1}}, 
Frame -> 
          True, 
FrameTicks -> 
          False, 
DisplayFunction -> $DisplayFunction]
, {t, 0, 2*π - 0.001, (2*π)/20}]