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Solving a differential equation I got to the following result

-(((R[n*Pi - t/w] Cos[t/w])/(n*Pi))

Then, using this solution, I create .

circuloedisco[t_, w_, R_, n_] :=
 Show[
  Graphics[
    {Circle[{0, 0}, R], {Cyan, Thickness[0.005], 
     Line[{{0, 
        0}, {(( w*t)/(n*Pi) - 1) R*
         Sin[w*t], (( w*t)/(n*Pi) - 1) R*
         Cos[w*t]}}]},
    {Red, PointSize[0.05], 
     Point[{(( w*t)/(n*Pi) - 1) R*
        Sin[w*t], (( w*t)/(n*Pi) - 1) R*
        Cos[w*t]}]},

    {Yellow, PointSize[0.08], Point[{0, R}]},
    {Green, PointSize[0.08], Point[{0, -R}]}}, AspectRatio -> 1,
   Axes -> True],
  ParametricPlot[{(( w*T)/(n*Pi) - 1) R*
     Sin[w*T], ((w*T)/(n*Pi) - 1) R*
     Cos[w*T]}, {T, 0.001, t}]
  ]

After this I create a Manipulate to simulate, but I have two problems. When I change the values of w and r, nothing happens in the blue path of the phenomenon.

Manipulate[ 
  GraphicsRow[{circuloedisco[t, w, R, n]}], 
  {t, 0, (2*n* Pi)/w, 0.0001}, 
  {w, 2.05, 18.21}, 
  {{R, 5}, 2 , 10}, 
  {n, 1, 7, 1},
  ControlPlacement -> Top,
  SaveDefinitions -> True]

I would like to make this Manipulate in 3D. Anyone know how? And why do the controls for w and r change nothing?

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closed as off-topic by m_goldberg, Yves Klett, MarcoB, user9660, RunnyKine Mar 15 '16 at 16:52

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "This question arises due to a simple mistake such as a trivial syntax error, incorrect capitalization, spelling mistake, or other typographical error and is unlikely to help any future visitors, or else it is easily found in the documentation." – m_goldberg, Yves Klett, MarcoB, Community, RunnyKine
If this question can be reworded to fit the rules in the help center, please edit the question.

  • $\begingroup$ I believe the only problem is the use of pi where you meant to write Pi -- capitalization matters. With that one change I get an apparently working Manipulate: i.stack.imgur.com/6LQoi.png $\endgroup$ – Mr.Wizard Mar 14 '16 at 19:59
  • $\begingroup$ Yeah, it works. I think in the copy/paste i had some troubles, but when you change some variables the simulation still the same, in theory should change the path. $\endgroup$ – dcvilela Mar 14 '16 at 20:16
  • $\begingroup$ The problem with your r variable is caused by the automatic scaling of the plot. If you look carefully you will see that when r is changed, the coordinate system ticks change value rather than the radius of the disk. $\endgroup$ – m_goldberg Mar 15 '16 at 11:01
  • $\begingroup$ @dcvilela - How do you want to make this 3D? Everything I see is 2D, what would the z dimension be? $\endgroup$ – Jason B. Mar 15 '16 at 12:13
  • $\begingroup$ @JasonB, something like this! $\endgroup$ – dcvilela Mar 15 '16 at 12:46
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When the plot range is fixed, your controls all seem to work. Try adding a plot range option to circuloedisco as follows:

circuloedisco[t_, w_, R_, n_] :=
  Show[
   Graphics[...],
   ParametricPlot[...],
   PlotRange -> {{-10, 10}, {-10, 10}}]

Then

Manipulate[circuloedisco[t, w, R, n],
  {t, 0, (2*n*Pi)/w, 0.0001},
  {w, 2.05, 18.21},
  {{R, 5}, 2, 10},
  {n, 1, 7, 1},
  ControlPlacement -> Top,
  SaveDefinitions -> True]

will look like this

demo

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