arctools (version 1.1.6)

summarize_PA: Compute physical activity summaries of minute level activity data.

Description

Compute physical activity summaries of minute level activity data.

Usage

summarize_PA(
  acc,
  acc_ts,
  wear_flag,
  valid_day_flag,
  sedentary_thresh = 1853,
  subset_minutes = NULL,
  exclude_minutes = NULL,
  subset_weekdays = NULL,
  in_bed_time = NULL,
  out_bed_time = NULL,
  adjust_out_colnames = TRUE
)

Value

A data frame with physical activity summaries of minute level activity data. See README or vignette for summaries description.

Arguments

acc

A numeric vector. A minute-level activity counts data vector. It is assumed to be in midnight-to-midnight format, meaning its vector length is a multiple of number of minutes in a full day (1440). See arctools::midnight_to_midnight().

acc_ts

A POSIXct vector. Time of activity data collection, corresponding to acc in its original format (not: midnight-to-midnight). We strongly recommended to use lubridate::ymd_hms() function to create acc_ts (see Examples below).

wear_flag

An integer vector. It has value 1 if a minute belongs to a wear time-interval, value 0 if a minute belongs to a non-wear time-interval, and value NA to denote minutes before/after data collection started/finished. See arctools::get_wear_flag().

valid_day_flag

An integer vector. It has value 1 if a minute belongs to a valid day, and 0 otherwise. See arctools::get_valid_day_flag().

sedentary_thresh

A numeric scalar. If an activity count value falls below it then a corresponding minute is characterized as sedentary; otherwise, a corresponding minute is characterized as active. Default is 1853.

subset_minutes

Integer vector. Contains subset of a day's minutes within which activity summaries are to be computed. May take values from 1 (day's minute from 00:00 to 00:01) to 1440 (day's minute from 23:59 to 00:00). Default is NULL, i.e. no subset used (all day's minutes are used).

exclude_minutes

Integer vector. Contains subset of a day's minutes to be excluded from activity summaries computation. May take values from 1 (day's minute from 00:00 to 00:01) to 1440 (day's minute from 23:59 to 00:00). Default is NULL, i.e. no minutes excluded (all day's minutes are used).

subset_weekdays

Integer vector. Specfies days of a week within which activity summaries are to be computed. Takes values between 1 (Sunday) to 7 (Saturday). Default is NULL, i.e.no subset used (all days of a week are used).

in_bed_time

A POSIXct vector. An estimated in-bed time start. Together with a corresponding entry from out_bed_time vector, it defines a day-specific subset of "in bed time" minutes to be excluded from activity summaries computation. Default is NULL, i.e. no minutes excluded.

out_bed_time

A POSIXct vector. An estimated in-bed time end. Together with a corresponding entry from in_bed_time vector, it defines a day-specific subset of "in bed time" minutes to be excluded from activity summaries computation. Default is NULL, i.e. no minutes excluded.

adjust_out_colnames

A logical scalar. Whether or not to add an informative suffix to column names in the output data frame. This may happen in case any of the arguments: subset_minutes, or exclude_minutes, or in_bed_time and out_bed_time are set other than NULL. Default is TRUE.

Examples

## Read exemplary data
fpath_i <- system.file("extdata", extdata_fnames[1], package = "arctools")
dat_i   <- as.data.frame(data.table::fread(fpath_i))
acc     <- dat_i$vectormagnitude
acc_ts  <- lubridate::ymd_hms(dat_i$timestamp)
## Get acc data vector in "midnight_to_midnight" format
acc <- midnight_to_midnight(acc, acc_ts)
## Get wear/non-wear flag
wear_flag <- get_wear_flag(acc)
## Get valid/non-valid day flag
valid_day_flag <- get_valid_day_flag(wear_flag)
## Impute missing data in acc data vector
acc_imputed <- impute_missing_data(acc, wear_flag, valid_day_flag)

## Example 1
## Summarize PA
summarize_PA(acc, acc_ts, wear_flag, valid_day_flag)

## Example 2
## Summarize PA within minutes range corresponding to 12:00 AM - 6:00 AM
subset_12am_6am <- 1 : (6 * 1440/24)
summarize_PA(acc, acc_ts, wear_flag, valid_day_flag, subset_minutes = subset_12am_6am)

## Example 3
## Summarize PA without (i.e., excluding) minutes range corresponding to 11:00 PM - 5:00 AM.
subset_11pm_5am <- c(
  (23 * 1440/24 + 1) : 1440,   ## 11:00 PM - midnight
  1 : (5 * 1440/24)            ## midnight - 5:00 AM
)
summarize_PA(acc, acc_ts, wear_flag, valid_day_flag, exclude_minutes = subset_11pm_5am)