g.readaccfile: Generic functiont to read large blocks of accelerometer data

In GGIR: Raw Accelerometer Data Analysis

Generic functiont to read large blocks of accelerometer data

Description

The function is used by g.getmeta and g.calibrate to read large blocks of the accelerometer file, which are processed and then deleted from memory. This is needed for memory management.

Usage

  g.readaccfile(filename, blocksize, blocknumber, filequality,
                           ws, PreviousEndPage = 1, inspectfileobject = c(),
                           PreviousLastValue = c(0,0,1), PreviousLastTime = NULL,
                           params_rawdata = c(), params_general = c(), header = NULL, ...)

Arguments

filename	filename
blocksize	Size of blocks (in file pages) to be read
blocknumber	Block number relative to start of file, starting with 1.
filequality	Single row dataframe with columns: filetooshort, filecorrupt, and filedoesnotholdday. All with the value TRUE or FALSE
ws	Larger windowsize for non-detection, see documentation g.part2
PreviousEndPage	Page number on which previous block ended (automatically assigned within g.getmeta and g.calibrate).
inspectfileobject	Output from the function g.inspectfile.
PreviousLastValue	Automatically identified last value in previous chunk of data read.
PreviousLastTime	Automatically identified last timestamp in previous chunk of data read.
params_rawdata	See g.part1
params_general	See g.part1
header	Header information that was extracted the previous time this file was read, to be re-used instead of being extracted again.
...	Any input arguments needed for function read.myacc.csv if you are working with a non-standard csv formatted files. Furter, any argument used in the previous version of g.readaccfile, which will now be used to overrule the arguments specified with the parameter objects.

Value

• P Block object extracted from file with format specific to accelerometer brand

• filequality Same as in function arguments

• isLastBlock Boolean indicating whether this was the last block to read

• endpage Page number on which blocked ends, this will be used as input for argument PreviousEndPage when reading the next block.

Author(s)

Vincent T van Hees <[e-mail]>

Examples

  ## Not run: 
    filequality = data.frame(filetooshort = FALSE, filecorrupt = FALSE,
    filedoesnotholdday = FALSE)
    output = g.readaccfile(filename = "C:/myfile.bin", 
    blocksize = 20000, blocknumber = 1,
    selectdaysfile = c(), filequality = filequality,
    dayborder = 0, PreviousEndPage = c()) 
  
## End(Not run)

GGIR documentation built on Sept. 11, 2024, 8:59 p.m.