sgarciav

  bool angleBetweenVectors(Eigen::Vector3f u, Eigen::Vector3f v, double& angle_rad)
  {
    float dot_product = u.dot(v);
    float norms = u.norm() * v.norm();

    // Avoid division by zero or invalid acos input
    if (norms == 0) {
      RCLCPP_ERROR(this->get_logger(), "One or both vectors have zero magnitude.");
      return false;
    }

sgarciav

See: https://askubuntu.com/questions/1241202/cant-access-webcam-settings

  $ sudo apt install v4l-utils
  $ v4l2-ctl --list-devices
  $ v4l2-ctl -d /dev/videoX --list-ctrls
  $ v4l2-ctl --device /dev/video3 --set-ctrl=zoom_absolute=120

sgarciav

Instructions

Taken from here:

  ip a # get DEVICE
  sudo ifconfig <DEVICE> up
  nmcli dev wifi list # get SSID
  sudo nmcli --ask dev wifi connect <SSID>

sgarciav

1. Find the page that hosts the keyworkd:

   pdfgrep -in <keyword> <pdf-file>

2. Extract specific pdf page:

pdftk cat output

sgarciav

About

When you first install Docker, you have to execute its commands with sudo. Follow these steps to add your user to the docker group such that there won't be a need to execute with sudo.

See: https://docs.docker.com/engine/install/linux-postinstall/

Steps

• Add the docker group if it doesn't already exist:

sgarciav

Alternative method for displaying an image

This method relies on a static folder. Doesn't work when hosted on the web - which is why I needed to leverage the Google Cloud Storage.

@app.route('/display/<filename>')
def display_image(filename):
    return redirect(url_for('static', filename='processed_imgs/' + filename), code=301)

Syntax to use in html file if wanting to use the display_image function

sgarciav

References

• Python Django Tutorial for Beginners
• Deploy Your Script as a Flask App
• Google App Engine's config file (app.yaml)
• Integrate web app with Google Ads
• GCloud Python3 Runtime Environment
• Map your web app to a custom domain
• App Engine and Google Storage Sample
• [Setting Up Google Cloud Storage](https://cloud.google.com/appengine/docs/legacy/standard/python/googlecloudstorageclient/setting-up-cloud-storage#activating_a_clou

sgarciav

About

Instructions for using git lfs to track large file (greater tham 100MBs). See instructions here.

You can also watch this video to learn about the different features that lfs provides.

$ sudo apt install git-lfs
$ cd /path/to/[GIT REPO]
$ git lfs install
$ git track [filename or type of file you wish to track]

sgarciav

About

Sometimes a Docker container can get stuck in the "Removal in progress" status. If and when this happens it just hangs forever. Running docker rm -f doesn't work. The following set of instructions is a good workaround.

1. Stop the docker daemon ($ sudo systemctl stop docker.socket)
2. Remove the remaining container files ($ sudo rm -rf /var/lib/docker/containers/[FULL CONTAINER ID])
3. Start the docker daemon ($ sudo systemctl restart docker.socket).

sgarciav

See: https://askubuntu.com/questions/1230016/headset-microphone-not-working-on-ubuntu-20-04#1232155\

Execute the following:

$ mv ~/.config/pulse ~/.config/pulse_old
$ pulseaudio -k && sudo alsa force-reload

Your system should now recognize your buds' mic.