coa_locs: Calculate Centers of Activity
In bsmity13/ADePTR: Acoustic Detection Processing and Visualization Tool in R

Description Usage Arguments Details Value References See Also Examples

This function calculates Centers of Activity (COAs) by averaging the locations of detections in a user-defined time period.

1 2	coa_locs(proc_det, Delta_t = "1 hour", mean_type = c("arithmetic", "harmonic"))

`proc_det`	A `data.frame` of class `dets` as returned by the function `proc_dets()`.
`Delta_t`	The desired time interval for the COAs (Δt). Can be any value that can be accepted by the `by` argument of `seq.POSIXt()`.
`mean_type`	The type of mean used to calculate the mean positions. Should be either `"arithmetic"` or `"harmonic"`.

This function implements the two mean position algorithms suggested by Simpfendorfer et al. (2002) for calculating centers of activity (COAs).

Returns an object of class coa (also class sf and class data.frame) with georeferenced centers of activity.

Simpfendorfer, C.A., M.R. Heupel, and R.E. Hueter. (2002). Estimation of short-term centers of activity from an array of omnidirectional hydrophones and its use in studying animal movements. Canadian Journal of Fisheries and Aquatic Sciences 59(1): 23-32.

proc_dets for details on the formatting of the data.frame proc_det

See Simpfendorfer et al. (2002) for details on using COAs to study marine animal movements.

#Load data
data(acoustic)

##Conventional workflow
#Process detections
proc.det <- proc_dets(det = acoustic$detections,
                      sta = acoustic$stations)

#Default COAs (60 minutes, arithmetic mean)
coas.60 <- coa_locs(proc.det)

##Tidy workflow
coas.6h <- proc_dets(det = acoustic$detections,
                     sta = acoustic$stations) %>%
           spd_filter() %>%
           singleton_filter() %>%
           coa_locs(Delta_t = "6 hours")