# Velocity data

Each .vlg file contains as many groups as many recordings were made. Each recording has a unique identifier eg.: 12EB29805B3652C7 that is the name of the group.

The groups have two datasets:

time
  An array of 64 bit floats that contain the time in milliseconds
velocity
  An array of 64 bit floats that contain the velocity in counts/second. One full rotation of the disk is 14400 counts.

# Metadata

The metadata of each recording is saved as an attribute of the group:

id
  The id of the record set by the user
comment
  The comment of the record set by the user
mean_velocity
  The mean of the velocity in this record
date_hr
  The date of the record in a human readable format (%Y.%m.%d.)
start_time
  The start time of the record in UNIX format
start_time_hr
  The start time of the record in a human readable format (%H:%M:%S)
finish_time
  The finish time of the record in UNIX format
finish_time_hr
  The finish time of the record in a human readable format (%H:%M:%S)
length
  The length of the record in seconds
length_hr
  The length of the record in a human readable format (%M:%S)
device_serial
  The serial number of the device the recording was made with
sampling_freq
  The target sampling frequency set in the software (actual value might be different)
software_version
  What version of GramophoneTools was used to make this log