[plotting] movie example

plotting/code/movie_example.m

@@ -0,0 +1,54 @@
+clear all
+close all
+max_frames = 500;
+
+f_x = 1;
+f_y = 1.5;
+dt = 2*pi/500;
+
+f = figure();
+set(f, 'visible', 'off');
+set(f, 'PaperUnits', 'centimeter', 'PaperSize', [2.5, 2.5], ...
+    'PaperPosition', [0, 0, 2.5, 2.5], 'Color', 'white')
+
+writer = VideoWriter('../lecture/images/lissajous.mp4', 'MPEG-4');
+writer.FrameRate = 25;
+writer.Quality = 50;
+
+open(writer);
+for i = 1:max_frames
+    x = sin(f_x * 2 * pi * dt * i);
+    y = sin(f_y * 2 * pi * dt * i);
+    scatter(x, y, 30, 'r', 'filled');
+    xlim([-1.05, 1.05])
+    xticks([-1., 0., 1.])
+    ylim([-1.05, 1.05])
+    yticks([-1., 0., 1.])
+    xlabel('x')
+    ylabel('y')
+    drawnow;
+    frame = getframe(f);
+    writeVideo(writer, frame);
+end
+close(writer)
+
+x_positions = zeros(max_frames, 1);
+y_positions = zeros(max_frames, 1);
+for i = 1:max_frames
+    x_positions(i) = sin(f_x * 2 * pi * dt * i);
+    y_positions(i) = sin(f_y * 2 * pi * dt * i);
+end
+
+f = figure();
+set(f, 'PaperUnits', 'centimeter', 'PaperSize', [5, 5], ...
+    'PaperPosition', [0, 0, 5, 5], 'Color', 'white')
+
+scatter(x_positions, y_positions, 10, 'r', 'filled');
+xlim([-1.05, 1.05])
+xticks([-1., 0., 1.])
+ylim([-1.05, 1.05])
+yticks([-1., 0., 1.])
+xlabel('x')
+ylabel('y')
+
+saveas(f, '../lecture/images/lissajous.png')