Plot with lagging

Hi, I want to plot series of data (y vs. x) with lagging of time t (33.33mS) between each point and then to save that as a video (.avi format). Any assistance will be appreciated, Regards,

Answer 1

[Ayush]

Hi,

To create a video from a series of data points with a specific time lag between each point in MATLAB, you can follow these steps:

• Have your “x” and “y” data ready.
• Use “VideoWriter” function to create an .avi file.
• Loop through your data points, updating the plot for each point with the specified time lag.
• Capture each frame using “getframe” and write it to the video file.

Refer to an example code below for a better understanding:

% Sample data
x = 1:100; % Example x data
y = sin(x); % Example y data

% Time lag in seconds
time_lag = 0.03333; % 33.33 milliseconds

% Set up the video writer
videoFileName = 'data_plot.avi';
v = VideoWriter(videoFileName);
v.FrameRate = 1 / time_lag; % Set frame rate based on time lag
open(v);

% Create a figure for plotting
figure;
hold on;
grid on;
xlabel('X-axis');
ylabel('Y-axis');
title('Data Plot with Time Lag');

% Plot each point with the specified time lag
for i = 1:length(x)
    plot(x(i), y(i), 'bo'); % Plot the current point
    drawnow; % Update the plot
    
    % Capture the frame
    frame = getframe(gcf);
    writeVideo(v, frame);
    
    % Pause for the specified time lag
    pause(time_lag);
end

% Close the video writer
close(v);

disp(['Video saved as ', videoFileName]);

For more information on the “VideoWriter” and “getframe” functions refer to the below documentations:

• “VideoWriter”: https://www.mathworks.com/help/matlab/ref/videowriter.html
• “getframe”: https://www.mathworks.com/help/matlab/ref/getframe.html