Save the quiver plot as a video

Hello, I am trying to save the quiver plot as a .avi movie. I am including my code here:

      hFig = figure;  
      subplot(1,2,1);
      set(hFig, 'Position', [0 0 1000 1000]);  % to define Figure Properties
      stlgeometrie=stlread('gehause_Bmuster.stl');
      geoplot(stlgeometrie);
      axis([-200 200 -200 200 -200 200]);
      view([0 0]);
      hold on;

      subplot(1,2,2);
      set(hFig, 'Position', [0 0 1000 1000]);  % to define Figure Properties
      stlgeometrie=stlread('gehause_Bmuster.stl');
      geoplot(stlgeometrie);
      axis([-200 200 -200 200 -200 200]);
      view([60 0]);
      hold on;

for e = 1:length(range);
      a=0.1;
    subplot(1,2,1);
      q1 = quiver3(x,y,z, a*mag_X(21,:)'.*cos(Ph_X(21,:)'+range(e)), a*mag_Y(21,:)'.*cos(Ph_Y(21,:)'+range(e)), a*mag_Z(21,:)'.*cos(Ph_Z(21,:)'+range(e)),0,'MarkerSize',3,'LineWidth',1.5,'MaxHeadSize',0.1);
     subplot(1,2,2);

      q2 = quiver3(x,y,z, a*mag_X(21,:)'.*cos(Ph_X(21,:)'+range(e)), a*mag_Y(21,:)'.*cos(Ph_Y(21,:)'+range(e)), a*mag_Z(21,:)'.*cos(Ph_Z(21,:)'+range(e)),0,'MarkerSize',3,'LineWidth',1.5,'MaxHeadSize',0.1);
      M{e} = getframe;
      Fz(e) = mag_Z(100,1)'.*cos(Ph_Z(100,1)'+range(e));
      delete(q1);
      delete(q2);
  end
  movie(cell2mat(M));
  movie2avi(cell2mat(M),'MyMovie.avi','Compression','None');

When I use the following code, I can only see the video of second sub-plot and the video doesn't contain the video, but just a image of the second sub-plot. I just want to save the video which gets displayed because of the quiver command. I am also attaching my workspace variables with this query! Thank you in advance!

Answer 1

[Walter Roberson]

M{e} = getframe(gcf);

Note: this will capture the entire figure, including window decorations. getframe() captures an axes or a figure, but you are creating multiple axes so you need to save the figure.

[Karthik Brs]

Thanks for the reply! I have used getframe(gcf), but it gives me the same output. The only thing different is that the video contains window decorations and the windows taskbar. The video doesn't contain the animation of the vectors. Instead, it creates a huge video file(150 Mb) of duration 8 secs containing just an image of the quiver plot. I guess the video contains only the last frame! Please help!

[Walter Roberson]

I suggest trying

M(e) = getframe(gcf);

and movie(M) and

movie2avi(M,'MyMovie.avi','Compression','None');

If nothing else these should be a little more efficient.

Also I recommend using an explicit 'fps' parameter even if you do want the default 15 fps -- it makes it clear to other people reading that you thought about the frame rate.

But movie2avi() is going away soon and it is recommended that you switch to VideoWriter, which might also cure the problem with last frame.

fps = 15;  %to match movie2avi
v = VideoWriter('MyMovie.avi', 'Uncompressed AVI', 'FrameRate', fps);
open(v);
writeVideo(v, M);
close(v);

[Karthik Brs]

Thank you again for ur time. But the code still doesn't work. I am attaching the video file which I am getting after altering my code according to yours. You can try and run the code if you wish. The workspace variables can be found in the original attachment.

% Quiver vector field animation

        hFig = figure;  
        set(hFig, 'Position', [0 0 2000 2000]);  % to define Figure Properties
        stlgeometrie=stlread('gehause_Bmuster.stl');
        geoplot(stlgeometrie);
        axis([-200 200 -200 200 -200 200]);
        view([0 0]);
        hold on;

    for e = 1:length(range);

    q1 = quiver3(x,y,z, a*mag_X(21,:)'.*cos(Ph_X(21,:)'+range(e)), a*mag_Y(21,:)'.*cos(Ph_Y(21,:)'+range(e)), a*mag_Z(21,:)'.*cos(Ph_Z(21,:)'+range(e)),0,'MarkerSize',3,'LineWidth',1.5,'MaxHeadSize',0.1);
    M(e) = getframe(gca);
    delete(q1);
    end

    fps = 15;  %to match movie2avi
    v = VideoWriter('MyMovie.avi', 'Uncompressed AVI', 'FrameRate', fps);
    open(v);
    writeVideo(v, M);
    close(v);

[Walter Roberson]

I think it is time for me to go to bed (in a literal sense.)

[Karthik Brs]

Would be glad if you could get back to me tomorrow! :)