GGIR (version 3.2-0)

g.readaccfile: 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, ...)

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.

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.

Author

Vincent T van Hees <[e-mail]>

Examples

  if (FALSE) {
    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()) 
  }