三角比

球面を描く

ParametricPlot3D[{Cos[t]*Cos[s], Cos[t]*Sin[s], Sin[t]}, {t, -Pi/2, 
        Pi/2}, {s, -Pi, Pi}]

ParametricPlot3D[{Cos[t]*Cos[s], Cos[t]*Sin[s], Sin[t]}, {t, 0, 
        Pi/2}, {s, 0, 2 Pi}, Boxed -> False]

ParametricPlot3D[{Cos[t]*Cos[s], Cos[t]*Sin[s], Sin[t]}, {t, -Pi/2, 
        0}, {s, -Pi, 0}]

ar = 
        N[Table[{Cos[t]*Cos[s], Cos[t]*Sin[s], Sin[t]}, {t, -Pi/2, Pi/2, 
                Pi/24}, {s, -Pi, Pi, Pi/24}]] // 
          Flatten[#, 1] &;

N[Table[{Cos[t]*Cos[s], Cos[t]*Sin[s], Sin[t]}, {t, -Pi/2, Pi/2, 
          Pi/24}, {s, -Pi, Pi, Pi/24}]]

pt = Map[Point, ar];

Show[Graphics3D[pt, Boxed -> False]]

?Point

?Boxed

海水浴場で

Do[DensityPlot[Sin[x - y + t], {x, 0, 6 Pi}, {y, 0, 6 Pi}, 
        PlotPoints -> 200, Mesh -> False], {t, 0, 11 Pi/6, 
        Pi/6}]

Do[DensityPlot[Sin[x - y + t], {x, 0, 6 Pi}, {y, 0, 6 Pi}, 
        PlotPoints -> 200, Mesh -> True], {t, 0, 11 Pi/6, 
        Pi/6}]

DensityPlot[Sin[x y], {x, 0, 7 Pi}, {y, 0, 7 Pi}, 
      PlotPoints -> 500, Mesh -> False]

?DensityPlot

?Mesh