Aggregate Accelerometry Data

Description

This function aggregates count values

Usage

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aggAccFile(object, by, which = "counts",
	x = NULL, keep.error = FALSE)

Arguments

object

an object of class accfile.

by

epoch by which count and steps are aggregated. Note: it cannot be less that the accelerometer epoch (object$info$epoch).

which

either 'counts' or 'steps' for gt1m files or one of c('x','y','z','steps') for gt3x files.

x

optional argument. If NULL, this is set to counts.

keep.error

logical flag. Should errors be omitted?

Value

outcome

aggregated values

ts_agg

time stamping

Author(s)

Marco Geraci

References

Geraci M, Rich C, Sera F, Cortina-Borja M, Griffiths LJ, and Dezateux C (2012). Technical report on accelerometry data processing in the Millennium Cohort Study. London, UK: University College London. Available at http://discovery.ucl.ac.uk/1361699

See Also

collapse.accfile

Examples

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data(gt1m_sample)

# aggregate by 30-second epochs
aggAccFile(gt1m_sample, by = 30)

# aggregate by 5-minute epochs
aggAccFile(gt1m_sample, by = 300, keep.error = FALSE)