In wadpac/GGIR: Raw Accelerometer Data Analysis

In this cook book you will find recipes for using GGIR in specific non-default scenarios.

Handling externally derived epoch data

This refers to the situation where external software or hardware was used to derive epoch level aggregates from accelerometer data.

In this section you will find key parameters needed for working with these data formats. Please refer to the other parts of the GGIR documentation for guidance on how to tailor the rest of your analysis towards your study protocol and research interests.

Please be aware the date-time formats may be country specific. So, when working with externally derived epoch data always check that parameter extEpochData_timeformat setting is correct for the data you are processing. You can do this by opening one of the files in notepad or eclipse. See our Annex page for guidance on how to specify date and time formats in R.

Actiwatch data

in .AWD format

This is a text file saved with .AWD extension. An example of how the first couple of hundred lines of an .AWD file may look like can be found here.

GGIR(datadir = "/media/actiwatch_awd", # folder with epoch level .AWD file
  outputdir = "/media/myoutput",
  dataFormat = "actiwatch_awd",
  extEpochData_timeformat = "%d-%b-%Y %H:%M:%S",
  windowsizes = c(60, 900, 3600), # 60 is the expected epoch length
  acc.metric = "ExtAct")

To classify sleep from Actiwatch, consider parameter HASIB.algo = "Oakley1997".

in .CSV format

An example of how the first couple of hundred lines of this file may look like can be found here. Note that the example file is in Dutch but it should also work for files in English.

GGIR(datadir = "/media/actiwatch_csv", # folder with epoch level .AWD file
  outputdir = "/media/myoutput",
  dataFormat = "actiwatch_csv",
  extEpochData_timeformat = "%m/%d/%y %I:%M:%S %p",
  windowsizes = c(15, 900, 3600),
  acc.metric = "ExtAct")

To classify sleep from Actical, consider parameter HASIB.algo = "Oakley1997".

UK Biobank data in .CSV format

This is only applicable the UK Biobank 5 second epoch csv exports and NOT to the raw accelerometer data (multiple values per second). Please see https://wadpac.github.io/GGIR/ for all documentation on processing raw accelerometer data.

GGIR(datadir = "/media/ukbiobank",
   outputdir = "/media/myoutput",
   dataFormat = "ukbiobank_csv",
   extEpochData_timeformat = "%m/%d/%Y %H:%M:%S",
   windowsizes = c(5, 900, 3600), # We know that data was stored in 5 second epoch
   desiredtz = "Europe/London", # We know that data was collected in the UK
   acc.metric = "LFENMO")

Please note that currently no method exists in GGIR to detect sleep from these 5 second aggregate files.

ActiGraph count data in .CSV format

Examples of how the first couple of hundred lines of these files may look like can be found here, here, and here.

GGIR(datadir = "/examplefiles",
   outputdir = "",
   dataFormat = "actigraph_csv",
   extEpochData_timeformat = "%m/%d/%Y %H:%M:%S",
   windowsizes = c(5, 900, 3600),
   do.neishabouricounts = TRUE,
   acc.metric = "NeishabouriCount_x",
   threshold.in = round(100 * (5/60), digits = 2),
   threshold.mod = round(2500 * (5/60), digits = 2),
   threshold.vig = round(10000 * (5/60), digits = 2))

Sensewear data in .xls format

Sensewear comes in xls(x) files with many column from which GGIR only uses: "METs" as indicator for acceleration where the uses can use MET levels as acceleration threshold, "Step Counter" which is treated as externally generated step count, and "Sleep" which is used as classification for sleep.

At a bare minimum the GGIR command to process these files looks as follows:

GGIR(datadir = "C:/yoursenseweardatafolder",
    outputdir = "D:/youroutputfolder",
    dataFormat = "sensewear_xls",
    extEpochData_timeformat = "%d-%b-%Y %H:%M:%S",
    windowsizes = c(60, 900, 3600),
    acc.metric = "ExtAct",
    threshold.in = 1.5,
    threshold.mod = 3,
    threshold.vig = 6)

To use the sleep classification as stored inside the data use parameter HASIB.algo = "data".

Actical in .csv format

An example of how the first couple of hundred lines of this file may look like can be found here

At a bare minimum the GGIR command to process these files looks as follows:

GGIR(datadir = "C:/youracticaldatafolder",
    outputdir = "D:/youroutputfolder",
    dataFormat = "actical_csv",
    extEpochData_timeformat = "%d-%b-%Y %H:%M",
    windowsizes = c(60, 900, 3600),
    acc.metric = "ExtAct")

To classify sleep from Actical, consider parameter HASIB.algo = "Oakley1997".

Philips Health Band in .xlsx format

The Philips Health Band data comes with .xlsx file pairs per recording. One starts with DataList the other one starts with Sleep_Wake_. Examples of how the first couple of hundred lines of such files may look like can be found here for DataList and here for Sleep_Wake.

At a bare minimum the GGIR command to process these files looks as follows:

GGIR(datadir = "C:/yourphbdatafolder",
    outputdir = "D:/youroutputfolder",
    dataFormat = "phb_xlsx",
    extEpochData_timeformat = "%m-%d-%Y %H:%M:%S",
    windowsizes = c(60, 900, 3600),
    acc.metric = "ExtAct")

When HASIB.algo = "data" GGIR attempts to extract and uses the sleep classification that is stored inside the xlsx files with column name "sleepWake". If no sleep classification is stored inside the data, GGIR uses the activity indicator as stored as "activitycounts". You can specify HASIB.algo = c("data", "Oakley1997") to make GGIR fall back on Oakley1997 if this would be the case.

Fitbit as folder with .json format files

Fitbit data comes with multiple .json file per recording (individual) stored in the same folder, with one folder for each recording.

GGIR uses the .json file names starting with sleep, calories, and steps for sleep, magnitude of movement, and steps, respectively.

Examples of how these files may look like can be found here for sleep, [here for steps](https://github.com/wadpac/GGIRread/blob/main/inst/testfiles/steps-1995-06-23_Fitbit.json, and here for calories.

At a bare minimum the GGIR command to process these files looks as follows:

GGIR(datadir = "C:/yourfitbitdatafolder",
    outputdir = "D:/youroutputfolder",
    dataFormat = "fitbit_json",
    windowsizes = c(60, 900, 3600),
    acc.metric = "ExtAct")

Note that parameter extEpochData_timeformat is not expected for Fitbit as we assume that the timestamps are always stored with the same internal format inside the .json files.

To use the sleep classification as stored inside the data use parameter HASIB.algo = "data".

Handling study protocol

Not worn during night

Data type: Any Study protocol: Worn during the day, taken off during the night Wear location: Any

GGIR(HASPT.algo = c("NotWorn", "HDCZA"),
    HASIB.algo = "vanHees2015",
    do.imp = FALSE, # Do not impute nonwear because sensor was never worn 24/7
    HASPT.ignore.invalid = NA, # Treat nonwear as potential part of guider window
    ignorenonwear = FALSE, # Consider nonwear as potential sleep
    includenightcrit = 8,
    includedaycrit = 8)

If "NotWorn" is specified then a second guider can be supplied to the same parameter as shown above. This second guider will be used if the accelerometer is worn for more than 75 percent of the night. The example above shows this for HDCZA.

wadpac/GGIR documentation built on June 15, 2025, 12:48 p.m.