How can i merge two log file

I have a few questions regarding the data log and data view.

  1. How can I log only some specific sensor(IMU, Baro. etc) data, not all sensor data?
  2. How can I merge 2 or more than 2 log files for viewing data on only one graph? Because during the test it creat 3 to 4 log files in SD card so I want how can I merge all log files for viewing test data on 1 graph.

Thank You.

  1. Use LOG_BITMASK parameter
  2. Not possible