lxy.thin.bursts: Thins out the 'bursts' in a GPS dataset
In tlocoh: Constructs homeranges and explores time use patterns from location data

Description Usage Arguments Value Note See Also

Thin out closely-timed bursts of locations

1
2
3

lxy.thin.bursts(lxy, id = NULL, thresh = NULL, replace = c("mean",
  "median")[2], info.only = FALSE, dt.int.round.to = 0.1,
  tau.diff.max = 0.02, status = TRUE)

`lxy`	A LoCoH-xy object
`id`	The id value(s) to be thinned
`thresh`	The threshhold for delta.t below which a pair of points is considered to be part of a burst, expressed either as a proportion of the median sampling frequency (0..1) or an absolute unit of time (in seconds)
`replace`	The burst replacement method ('mean' or 'median')
`info.only`	Show information about number of bursts (only)
`dt.int.round.to`	The proportion of the median sampling frequency that time intervals will be rounded to when computing the frequency table of sampling intervals (no change is made to the time stamps)
`tau.diff.max`	The maximum deviation from tau (the median delta.t of the entire dataset), expressed as a proportion of tau, that time difference between two points must fall for the distance between those two points to be included in the calculation of the median step length
`status`	Show status messages. T/F

a LoCoH-xy object

Many GPS devices have a feature to save 'bursts' of points close together in time (relative to the dominant sampling frequency) The 'burst' feature should not be confused with point averaging, whereby a GPS device internally averages locations for a period of time (e.g., 2 minutes) but saves a single location.

This function can be used to thin out 'bursts' of locations, when they are an artifact of data collection and therefore not desirable. Each group of points in a burst is replaced with a single point.

thresh is a numeric value for identifying which points should be considered part of a burst. When thresh < 1, it is taken to be a proportion of the median sampling frequency (0..1), and any pair of points that are recorded closer in time are considered part of a 'burst', When thresh > 1, it is taken to be absolute unit of time (in seconds).

To identify whether there are bursts in a LoCoH-xy dataset, and the sampling frequency of those bursts (i.e., the value

The two replacement methods are /codereplace="mean", in which case a burst of locations is replaced by a single point consisting of the spatial and temporal average of the burst, or /codereplace="median" in which case a burst of locations is replaced by the location at the temporal median of the burst. If /codereplace="mean", then any ancillary variables for the 'new' points will be set to NA.

Because this function deletes points, the nearest neighbor lookup table of the LoCoH-xy object (if any) will be deleted, and the parameters for random walk model will be recomputed.

lxy.plot.freq, lxy.thin.byfreq

tlocoh documentation built on May 2, 2019, 5:27 p.m.