Recording a graphics element to a video format

Hello,

I'm having some trouble finding a method to save this graphics animation to a video file. The initial 'array' is a 1200x8 matrix that I'm simply performing interpolation on between points. A .gif file would be the most useful format, but I haven't been successful saving the graphics element 'p' to this file type. Any help is appreciated.

Thanks.

array=-ppdtrace;
array_zeros=[zeros(size(array,1),1) array];
array_zeros=cat(2, zeros(size(array,1),1), array);
x = (0:8)';
xx=0:0.05:8;
yy=makima(x,array_zeros(1,:),xx);
figure(1)
p = plot(x,array_zeros(1,:)',xx,yy);
axis([0 9 -0.85 0]);
for k=2:1200
    pause(0.05)
    yy=makima(x,array_zeros(k,:),xx);
    set(p, 'XData', xx, 'YData', yy);
end

[Stephen23]

https://www.mathworks.com/help/matlab/ref/exportgraphics.html#mw_0216309c-493a-43ac-908a-6ad656b1fc82

Answer 1

[Epsilon]

Hi Owen,

To save the generated images into a gif, both ‘exportgraphics’ and ‘imwrite’ functions can be used. The ‘imwrite’ function can be used to write an image to a file location and append the subsequent images to create a gif with a controlled delay. Whereas the ‘exportgraphics’ function (in release R2022a and later) can directly save the graphics object into a gif file.

Attaching a sample code with 12 frames using both the functions:

array = rand(12, 8) * 2 - 1; 
array_zeros = [zeros(size(array, 1), 1), array, zeros(size(array, 1), 1)]; 
x = (0:9)';  
xx = 0:0.05:9;  
yy = makima(x, array_zeros(1, :), xx); 
figure(1) 
p = plot(x, array_zeros(1, :)', xx, yy); 
axis([0 9 -1 1]); 

filename = 'animation.gif'; 

%Using imwrite function 
for k = 1:12 
    pause(0.05) 
    yy = makima(x, array_zeros(k, :), xx); 
    set(p, 'XData', xx, 'YData', yy); 
    % Capture the current frame 
    frame = getframe(gcf); 
    img = frame2im(frame); 
    [imind, cm] = rgb2ind(img, 256); 
    % Write to the GIF file 
    if k == 1 
        % For the first frame, create the GIF file 
        imwrite(imind, cm, filename, 'gif', 'Loopcount', inf, 'DelayTime', 0.05); 
    else 
        % For subsequent frames, append to the GIF file 
        imwrite(imind, cm, filename, 'gif', 'WriteMode', 'append', 'DelayTime', 0.05); 
    end 
end 

%Using exportgraphics function 
for k = 1:12 
    pause(0.05) 
    yy = makima(x, array_zeros(k, :), xx); 
    set(p, 'XData', xx, 'YData', yy); 
   exportgraphics(gcf,"animation2.gif","Append",true);
end 

For further reference on both the functions please refer to the documentation links below:

• imwrite - https://www.mathworks.com/help/matlab/ref/imwrite.html
• exportgraphics - https://www.mathworks.com/help/matlab/ref/exportgraphics.html

Hope it helps.