pawacc (version 1.1)

gt3x.accfile: Read a single accelerometer file

Description

This function reads an Actigraph GT3X accelerometer file.

Usage

gt3x.accfile(file, path, fileid, tz = "Europe/London",
	sparse = FALSE)

Arguments

file

file name including file extension.

path

path to file.

fileid

label for file identifier.

tz

a character string specifying the timezone to be used for the conversion (see strptime).

sparse

logical flag: should data be stored in sparse format?

Value

• These functions return an object of two classes: accfile and additional device-specific class (i.e., gt3x). An object of class accfile is a list containing the following components:
• df
  A data.frame object with file identifier ('fileid'), accelerometer values in columns 'x', 'y', 'z', 'w'. If sparse = TRUE, a matrix named Data with accelerometer values is returned in sparse matrix format (see as.matrix.csr for details).
• info
  A data.frame object with file identifier ('fileid'), number of recorded measurements ('nobs'), epoch ('epoch'), accelerometer mode ('mode'), start date and time ('TimeStamp_orig'), time zone ('TZ'), battery voltage ('voltage'), download date and time ('TimeStamp_dl').

Details

Raw accelerometer data are processed according to the device data format. See file 'gt3x_sample.dat' in directory '\inst\extdata' of this package.

References

Actigraph (Pensacola, Florida).

See Also

readAccDir

Examples

data(gt3x_sample)
class(gt3x_sample)