Animate, video file problem.

Question

I have a function f(z,t) and I would like to animate it and also create a video file. For animation I do the following;

 Res1 = Sin[z t];
    vid = Animate[
    Plot[Res1, {z, 1, 2}, PlotRange -> {0, 1.1}], {t, 0, 1/3}];
    Print[vid];

This is not working, I am just getting a blank animation. When I do;

vid = Animate[
Plot[Sin[z t], {z, 1, 2}, PlotRange -> {0, 1.1}], {t, 0, 1/3}];
Print[vid];

this is working. I don't see why the first version is not working.

I also would like to save this animation as a movie. I don't think I can directly save that as a movie, but I found this;

frame[t_]:=ArrayPlot[Table[Sin[z t],{z,1,2}]];
frames=ParallelTable[frame[t],{t,0,1/3}];
Export["1stvid.mov",frames];

And I get an error. I am a little lost, I appreciate it some guidance.

Answer 1

It is a scoping issue. You need to add arguments to Res1 so that z and t have the same meaning inside the Animate

Res1[z_, t_] = Sin[z t];
vid = Animate[
  Plot[Res1[z, t], {z, 1, 2}, PlotRange -> {0, 1.1}], {t, 0, 1/3}]

Click on image above.

Export vid in whatever desired format.

Answer 2

I tend to just generate frames and Export:

frames = Table[
   Plot[Sin[z t], {z, 1, 2}, PlotRange -> {0, 1.1}],
   {t, 0, 1/3, 1/60}];
Export["test.avi", frames]

This lets us control exactly how many frames are generated, while Animate figures that automatically.