Text this: Visualizing mobile phone usage for exploratory analysis: A case study of Portugal

  ______   __   __  __    __     ___     _    _   
 /_   _//  \ \\/ // \ \\ / //   / _ \\  | || | || 
   | ||     \ ` //   \ \/ //   | / \ || | || | || 
  _| ||      | ||     \  //    | \_/ || | \\_/ || 
 /__//       |_||      \//      \___//   \____//  
 `--`        `-`'       `       `---`     `---`