1 years, 89 days

## Contour plot in polar coordinates...

Maple

Hi, I'm trying to plot equipotential lines and streamlines in Maple, and both equations are in polar coordinates. I can plot a contourplot in cartesian coordinates, but adding "coords=polar", it throws an error. I tried to write a do loop but it wasn't having it either. any help would be appreciated

restart; with(LinearAlgebra); with(plots);
K := 1;
psi := K*r^(4/3)*sin(4/3*theta);
phi := K*r^(4/3)*cos(4/3*theta);

p1 := contourplot(psi, r = 0 .. 1, theta = 0 .. 3*Pi*(1/8));

p2 := contourplot(phi, r = 0 .. 1, theta = 0 .. 3*Pi*(1/8));
display(p1, p2);

## Plot graph from array...

Maple 2018

Hi, I've created an array from a do loop, where the number in the array is the number of degrees for which I've calculated the answer, I now wish to graph the angle against the value in the array. i.e. the value a[50]=156.21 should graph to the point (50,156.21). Ideally as well I'd like for it to be joined up by a smooth curve of best fit, but I'll take what I can get, I can't seem to figure out how to plot it at all at the moment.

See code below:

restart;

for i from 50 by 5 to 85 do
ThetaBn := (1/180)*i*Pi;
s := cos(2*ThetaBn)*x+(2*sin(ThetaBn)*sin(ThetaBn))*sin(x);
a[i] := 180.0*fsolve(s = 0, x, 1 .. 6)*(1/Pi)
end do;

Thanks

## Trouble plotting graph in Maple...

Maple 2018

I'm trying to plot a graph of cos(2*theta)*omega*t+2*(sin(theta))^2*sin(omega*t)=0 in Maple (For values of theta between 40 and 88 degrees roughly, with a fixed value of omega). I have substituted x=omega*t and tried to solve, but as I'm sure you can tell it is not outputting the graph I'm after, I was hoping somebody would be able to tell me where I am going wrong. Thanks.

restart;
v := 145000;
thetavn := (1/6)*Pi;
omegac := .1;
s := cos(2*thetabn)*x+2*sin(thetabn)^2*sin(x);
plots:-implicitplot(s = 0, thetabn = 43*Pi*(1/180) .. 88*Pi*(1/180), x = -200 .. 200, tickmarks = ["piticks", "decimalticks"], gridrefine = 4, size = [800, 600]);

## Add straight line animation to existing ...

Maple 2018

I have this animation that displays a particle's position after reflection from a shock (the blue plane). I want to add a line that shows the particle coming in and reflecting and have them animate sequentially, but I cannot figure out how. The line should travel along the b axis, but offset in the xi axis to end where the helix begins. Here is the code for the helix animation:

restart; with(VectorCalculus); with(Student[LinearAlgebra]); with(plots);
v[i] := 145000; thetabn := (1/8)*Pi; thetavn := (1/6)*Pi; k := 10; omegac := .5;
v[b] := cos(2*thetabn)/cos(thetabn); v[g] := sin(2*thetabn)/cos(thetabn);
n := `<,>`(k*cos(thetabn), k*sin(thetabn), 0);
vr:=
[v[b]*t, v[g]*sin(omegac*t)/omegac, v[g]*cos(omegac*t)/omegac];

lambda := v[i]*cos(thetavn)/cos(thetabn);
shockplot := PlanePlot(n, caption = "", planeoptions = [colour = blue, transparency = .5], normaloptions = [shape = cylindrical_arrow, colour = red]);

t1 := textplot3d([k*cos(thetabn), k*sin(thetabn), 0, 'n'], align = above);

display(plots[animate](plot3d, [[v[b]*t, v[g]*sin(omegac*t)/omegac, v[g]*cos(omegac*t)/omegac], t = 0 .. x], x = 0 .. 6*Pi, axes = normal, colour = red, labels = ["b", zeta, xi], thickness = 2, paraminfo = false), shockplot, t1, scaling = constrained, tickmarks = [0, 0, 0]);

## How to plot data in a list?...

Maple 2018

Hi, I'm investigating an equation of motion, and I'm attempting to plot t against different values of thetabn. I have acquired a list of my data points (in the real domain) of the form [thetabn1, t1], [thetabn2, t2] ... etc. But I am struggling to figure out how to plot it. Using dataplot gives me a graph but it is incorrect. I would like a scatterplot, ideally once I have refined my range of thetabn I would like to be able to join it up with a line to create a nice looking plot. Also any improvements to my method would be appreciated. v[i], thetavn and omegac are set variables and s[n] is my function which I am setting equal to zero, and solving for t.

with(RealDomain);
v[i] := 145000;
thetavn := (1/6)*Pi;
omegac := .1;
s[n] := v[i]*cos(thetavn)*(cos(2*thetabn)*tan(thetabn)+sin(2*thetabn)*sin(omegac*t)/omegac);
for thetabn from evalf((1/100)*Pi) by evalf((1/100)*Pi) to evalf(Pi) do assign('result', [op(result), [thetabn, solve(v[i]*cos(thetavn)*(cos(2*thetabn)*tan(thetabn)+sin(2*thetabn)*sin(omegac*t)/omegac) = 0, t)]]) end do;
dataplot(result);

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