AG_collapse             Collapse primary accelerometer data
AG_insert               Calculate a new variable and insert it in a
                        data frame
AG_merge                Merge primary accelerometer data with IMU data
AG_meta                 Extract meta-data from file header
AGread                  Read Data Files from ActiGraph Monitors
check_columns           Check if the primary accelerometer file is
                        formatted correctly
check_second            Check if the IMU data start on an exact second
classify_magnetometer   Convert magnetometer signal to cardinal
                        direction
collapse_gt3x           Collapse data that were read using 'read_gt3x'
get_day_of_year         Julian Date
get_imu_file_meta       Get file metadata (sampling frequency, start
                        time, and samples per epoch) for IMU
get_minute              Numerical Minute of the Day.
get_raw_file_meta       Get file metadata (sampling frequency and
                        timestamps) for primary accelerometer
imu_collapse            Collapse raw IMU data to a specified epoch
imu_filter_gyroscope    Low-Pass filter Gyroscope data
imu_to_check            IMU data to check
imu_to_collapse         IMU data to collapse
raw_to_collapse         Primary accelerometer data to collapse
read_AG_IMU             File reading function for IMU files
read_AG_counts          Read data table files containing count values
read_AG_raw             File reading function for primary accelerometer
                        files
read_gt3x               Read data from a gt3x file
reintegrate             Reintegrate a data stream
