Theory/Tokamaks/Equilibrium/Helicity/plot.nb

Manipulate[
 Module[{rr = 2},

  torus[u_, v_] := {(rr + Cos[2 \[Pi] u]) Cos[
      2 \[Pi] v], (rr + Cos[2 \[Pi] u]) Sin[2 \[Pi] v], 
    Sin[2 \[Pi] u]};

  Toro = ParametricPlot3D[torus[u, v], {u, 0, 1}, {v, 0, 1}, 
    Boxed -> False, Axes -> False, MeshStyle -> None];

  Knot = ParametricPlot3D[torus[m u, 2 n u], {u, 0, 1}, 
    Boxed -> False, Axes -> False, 
    PlotStyle -> {Thickness[0.01], Blue}]];

 Show[Toro, Knot],
 {{m, 3}, 1, 15, 1}, {{n, 4}, 1, 15, 1}]
 
 
 see https://mathematica.stackexchange.com/questions/66025/plotting-knot-torus
 https://mathematica.stackexchange.com/questions/115414/curve-wound-on-torus
 http://demonstrations.wolfram.com/ToroidalHelices/