markpa.acclist: Classify mode of physical activity
In pawacc: Physical activity with accelerometers

Description Usage Arguments Details Value Author(s) See Also

This function identifies modes of physical activity using user-defined breakpoints for accelerometer counts.

markpa(object, value, which = "counts", rescale.epoch = 60, labels = NULL,
extreme = NULL, keep.error = FALSE)
## S3 method for class 'acclist'
markpa(object, value, which = "counts", rescale.epoch = 60, labels = NULL,
extreme = NULL, keep.error = FALSE)
## S3 method for class 'accfile'
markpa(object, value, which = "counts", rescale.epoch = 60, labels = NULL,
extreme = NULL, keep.error = FALSE)

`object`	an object of class `acclist` or `accfile`.
`value`	vector of breaks to define physical activity modes. The lowest breakpoint must be 0.
`which`	either 'counts' or 'steps' for `gt1m` files or one of `c('x','y','z','steps')` for `gt3x` files.
`rescale.epoch`	epoch expressed in the same unit as acceleromenter epoch to determine multiplier to rescale `value` (default is 60). See details.
`labels`	labels for physical activity modes.
`extreme`	if `value` includes a threshold for defining the category of extreme values, this argument identifies such category among the physical activity modes defined by `value`. See details.
`keep.error`	logical flag. If `FALSE` (default) data errors as identified by `errorChk` will be replaced by NAs.

Breakpoints are specified as counts per seconds using value. If the epoch used for value is different from the accelerometer epoch, a rescaling is applied. E.g., if epoch is 15 seconds and breakpoints are expressed as counts per 60 seconds, value is divided by 60/15 = 4. There can be n physical activity modes at maximum, where n is the length of value.

The argument extreme is NULL by default. Use either ‘last’ to select the last category or the category number 1 to n.

If object is of class acclist, a list of factors of the same length as the number of accelerometer files in object. If object is of class accfile, a single factor will be given. The number of levels is equal to length(value) + 1.

Marco Geraci

readAccDir

pawacc documentation built on May 2, 2019, 5:20 p.m.