Edited at bottom - I think the problem is my unwise expectation to overlay Plot___ over Graphics objects and magically have them scale.
I have an entry-level manipulate that shows how a cycloid is traced by a point on the surface of a rolling wheel. I'm sure I can improve on this (suggestions welcome), but the thing that has me stumped is how to overlay/include an incremental parametric plot of the cycloid itself.
Rolling wheel
Manipulate[
Graphics[{White, Rectangle[{0, -0.1}, {16, 3}], Blue,
Circle[{x, 1}, 1], Red,
Disk[{x - Sin[x - 1], 1 - Cos[x - 1]}, 0.1], Black,
Line[{{x, 1}, {x - Sin[x - 1], 1 - Cos[x - 1]}} ],
}], {x, 1, 14}]
That works the way I want it.
Try as I might, documentation (mis)reading notwithstanding I can't get this cycloid plot (Manipulates by itself without trouble (the arbitrary 22 for upper range is replaced by variable x when I try to embed in the Manipulate.
ParametricPlot[{t - Sin[t - 1], 1 - Cos[t - 1]}, {t, 1, 22},
PlotRange -> {{0, 24}, {0, 2}}]
if I put the ParametricPlot (with x in place of 22) after the closing ] of the Line I get Graphics is not a Graphics primitive or directive.
If I do this (i.e. make the "expr" of Manipulate a List, with element 1= Graphics[... element 2= ParametricPlot... I get a bunch of errors pointing at a variable called FE`x$$261 which shows up in place of the x near the <<
I am missing something here - anything appreciated even RTFM URLs.
Manipulate[
{Graphics[{White, Rectangle[{0, -0.1}, {16, 3}], Blue,
Circle[{x, 1}, 1], Red,
Disk[{x - Sin[x - 1], 1 - Cos[x - 1]}, 0.1], Black,
Line[{{x, 1}, {x - Sin[x - 1], 1 - Cos[x - 1]}} ],
}],
ParametricPlot[{t - Sin[t - 1], 1 - Cos[t - 1]}, {t, 1, x}, <<<HERE
PlotRange -> {{0, 24}, {0, 2}}]}, {x, 1, 14}]
EDIT: I replaced the convenient Disk etc. with actual parametric plots and now have some progress. Won't bore the experts with my incremental learnings - will update this post when I have made as much progress as I can. Ultimately I want to have the cycloid tracing onto the plot as the manipulate-slider progresses

Manipulate, e.g.{x, 1.00001, 14}instead of{x, 1, 14}. – Karsten7 Feb 04 '15 at 05:38Show. – Karsten7 Feb 04 '15 at 07:48