Skip to main content

plotting - How to graph a series of coupled oscillators and watch the wave move along them


Here are the differential equations that set's up the 11 coupled oscillators.



new = Join[
Table[x[i]''[t] == - x[i][t] +
0.1*(x[i + 1][t] - 2*x[i][t] + x[i - 1][t]), {i, 1,
9}], {x[0]''[t] == -x[0][t], x[10]''[t] == x[9][t], x[0][0] == 1,
x[0]'[0] == 1, x[1]'[0] == 0, x[1][0] == 0},
Table[x[i][0] == 0, {i, 2, 10}], Table[x[i]'[0] == 0, {i, 2, 10}]]

Here are the solutions.


Solt = NDSolve[new, Table[x[i], {i, 0, 10}], {t, 25}]


Here are the individual plots.


Table[Plot[Evaluate[x[i][t] /. Solt], {t, 0, 25}, 
PlotRange -> All], {i, 0, 10}]

I am trying to figure out how to make a graph so along the x-axis are my i's from 0 to 10, and I can watch the wave move along each oscillator as time moves on. I keep getting errors in which it floods my notebook and doesn't stop unless I close the kernel.


This is what I have so far, and I'm not sure how to incorporate time into this.


Plot[Evaluate[x[i][t] /. Solt], {i, 0, 10}]

EDIT Coupled in a circle


Stew = Join[

Table[x[i]''[t] == - x[i][t] +
0.1*(x[i + 1][t] - 2*x[i][t] + x[i - 1][t]), {i, 1,
9}], {x[10]''[t] == - x[10][t] +
0.1*(x[0][t] - 2*x[10][t] + x[9][t]),
x[0]''[t] == - x[0][t] +
0.1*(x[1][t] - 2*x[0][t] + x[10][t])}, {x[0][0] == 0,
x[0]'[0] == 0, x[1][0] == 1, x[1]'[0] == 0.5},
Table[x[i][0] == 0, {i, 2, 10}], Table[x[i]'[0] == 0, {i, 2, 10}]];

The Dsolve



Loin = NDSolve[Stew, Table[x[i], {i, 0, 10}], {t, 6.28}]

The individual graphs


Table[Plot[Evaluate[x[i][t] /. Loin], {t, 0, 6.28}, 
PlotRange -> All], {i, 0, 10}]

How would I go about putting the i=0 to 10 around in a circle?



Answer



After edit


I think oscillation directions should be parallel.



g[t_] = Table[{Cos[i*2 Pi/11], Sin[i*2 Pi/11], x[i][t]} /. Loin[[1]], {i, 0, 10}]; 

Animate[
Show[
ListPointPlot3D[g[t], PlotRange -> 1.5, BoxRatios -> 1, Filling -> Axis,
PlotStyle -> Directive@AbsolutePointSize@7, Boxed -> False],
ParametricPlot3D[{Cos@t, Sin@t, 0}, {t, 0, 2 Pi}, PlotStyle -> {Dashed, Black}]
,
ImageSize -> 500, ViewVector -> {{Cos[t/15], Sin[t/15], 1} 11, {0, 0, 0}},
AxesOrigin -> {0, 0, 0}, Ticks -> None, Axes -> True, AxesStyle -> {Red, Green, Blue},

SphericalRegion -> True],
{t, 0, 50}]

enter image description here


Before edit


f[t_] = Table[{i, x[i][t]} /. Solt[[1]], {i, 0, 10}];

Animate[
ListPlot[f[t], PlotRange -> {{0, 11}, {-1.5, 1.5}},
Joined -> True, PlotMarkers -> Automatic]

, {t, 0, 25}
]

Good to notice: In f[t] definition := is intentionally replaced by =.


enter image description here


Comments

Popular posts from this blog

plotting - Filling between two spheres in SphericalPlot3D

Manipulate[ SphericalPlot3D[{1, 2 - n}, {θ, 0, Pi}, {ϕ, 0, 1.5 Pi}, Mesh -> None, PlotPoints -> 15, PlotRange -> {-2.2, 2.2}], {n, 0, 1}] I cant' seem to be able to make a filling between two spheres. I've already tried the obvious Filling -> {1 -> {2}} but Mathematica doesn't seem to like that option. Is there any easy way around this or ... Answer There is no built-in filling in SphericalPlot3D . One option is to use ParametricPlot3D to draw the surfaces between the two shells: Manipulate[ Show[SphericalPlot3D[{1, 2 - n}, {θ, 0, Pi}, {ϕ, 0, 1.5 Pi}, PlotPoints -> 15, PlotRange -> {-2.2, 2.2}], ParametricPlot3D[{ r {Sin[t] Cos[1.5 Pi], Sin[t] Sin[1.5 Pi], Cos[t]}, r {Sin[t] Cos[0 Pi], Sin[t] Sin[0 Pi], Cos[t]}}, {r, 1, 2 - n}, {t, 0, Pi}, PlotStyle -> Yellow, Mesh -> {2, 15}]], {n, 0, 1}]

plotting - Plot 4D data with color as 4th dimension

I have a list of 4D data (x position, y position, amplitude, wavelength). I want to plot x, y, and amplitude on a 3D plot and have the color of the points correspond to the wavelength. I have seen many examples using functions to define color but my wavelength cannot be expressed by an analytic function. Is there a simple way to do this? Answer Here a another possible way to visualize 4D data: data = Flatten[Table[{x, y, x^2 + y^2, Sin[x - y]}, {x, -Pi, Pi,Pi/10}, {y,-Pi,Pi, Pi/10}], 1]; You can use the function Point along with VertexColors . Now the points are places using the first three elements and the color is determined by the fourth. In this case I used Hue, but you can use whatever you prefer. Graphics3D[ Point[data[[All, 1 ;; 3]], VertexColors -> Hue /@ data[[All, 4]]], Axes -> True, BoxRatios -> {1, 1, 1/GoldenRatio}]

plotting - Adding a thick curve to a regionplot

Suppose we have the following simple RegionPlot: f[x_] := 1 - x^2 g[x_] := 1 - 0.5 x^2 RegionPlot[{y < f[x], f[x] < y < g[x], y > g[x]}, {x, 0, 2}, {y, 0, 2}] Now I'm trying to change the curve defined by $y=g[x]$ into a thick black curve, while leaving all other boundaries in the plot unchanged. I've tried adding the region $y=g[x]$ and playing with the plotstyle, which didn't work, and I've tried BoundaryStyle, which changed all the boundaries in the plot. Now I'm kinda out of ideas... Any help would be appreciated! Answer With f[x_] := 1 - x^2 g[x_] := 1 - 0.5 x^2 You can use Epilog to add the thick line: RegionPlot[{y < f[x], f[x] < y < g[x], y > g[x]}, {x, 0, 2}, {y, 0, 2}, PlotPoints -> 50, Epilog -> (Plot[g[x], {x, 0, 2}, PlotStyle -> {Black, Thick}][[1]]), PlotStyle -> {Directive[Yellow, Opacity[0.4]], Directive[Pink, Opacity[0.4]],