Save animation as gif in Matlab GUI - matlab

Question

I am trying to save an animation as animated GIF.
My plot is similar to the given code below.
I created it with animated line too.
The problem is that:
When I defined my figure as f=figure or figure(1) it creates the .gif file properly.
However, instead of plotting my figure in separate screen using "figure" command, I have to plot in an axes on MATLAB GUI axes as the given figure.
I tried it with: f=(handles.axes_threeDOF);, But when I use this function, the gif file creates different part of the screen.
Could you help me to solve my problem?
numpoints = 500;
x = linspace(0,4*pi,numpoints);
y = square(x);
y2 = 3 +square(x+1);
f = figure
h = animatedline('Color','b','LineWidth',2);
h2 = animatedline('Color','r','LineWidth',2);
grid on;
axis([0,12,-3,+6])
for k = 1:numpoints
addpoints(h,x(k),y(k))
addpoints(h2,x(k),y2(k))
drawnow
% Capture the plot as an image
frame = getframe(f);
im = frame2im(frame);
[imind,cm] = rgb2ind(im,256);
% Write to the GIF File
if k == 1
imwrite(imind,cm,'test.gif','gif', 'Loopcount',inf);
else
imwrite(imind,cm,'test.gif','gif','WriteMode','append');
end
end
I want to create a gif of this animation:
But it creates as given below with this function " f=(handles.axes_threeDOF)"

Answer 1

I think I found the problem:
f = handles.axes_threeDOF gets the handle of the axes instead of getting the handle of the figure.
Since I don't know the name of your figure, I can't give a perfect solution.
You may try the following options:
1.Find the name of the figure, and use something like: f = handles.figure_threeDOF;
2. Use f = gcf();, assuming there is only one figure.
3. Use f = handles.axes_threeDOF.Parent; assuming the figure is the "Parent" of the axes.
Update:
After im = frame2im(frame);, you need to crop the relevant part of the image:
Something like: im = im(36:884, 928:1800, :);
There are more robust solution than using fixed indices, but it requires some knowledge about the internal structure of the figure.
Here is a code that reproduce the problem (instead of figure handle, f gets axes handle):
numpoints = 500;
x = linspace(0,4*pi,numpoints);
y = square(x);
y2 = 3 +square(x+1);
f = figure;
h = animatedline('Color','b','LineWidth',2);
h2 = animatedline('Color','r','LineWidth',2);
grid on;
axis([0,12,-3,+6])
for k = 1:numpoints
addpoints(h,x(k),y(k))
addpoints(h2,x(k),y2(k))
drawnow
%%% Test %%%
%The following code demonstrates the problem.
%f = gca(), returns a handle to the axes, instead of the figure.
%You should remove the following line for the code to work properly...
f = gca();
%%% Test %%%
% Capture the plot as an image
frame = getframe(f);
im = frame2im(frame);
[imind,cm] = rgb2ind(im,256);
% Write to the GIF File
if k == 1
imwrite(imind,cm,'test.gif','gif', 'Loopcount',inf);
else
imwrite(imind,cm,'test.gif','gif','WriteMode','append');
end
end
Result of correct code (without f = gca();):
Result of wrong code (with f = gca();) - getting axes handle instead of figure handle: