encounterDuration: Compute duration of encounters between groups
In moveBB: Analysis of Trajectory Data using Linear or Brownian Motion Model

Description Usage Arguments Details Value See Also Examples

Computes the duration of encounters between each pair of groups over the whole measurement period of a trajectory. The user can select what movement model(s) to apply and whether the result should be on the level of bursts or IDs. encounterDurationById returns the duration of encounters for each pair of IDs, given the duration of encounters for each pair of bursts. This allows to obtain both types of result without recomputing everything.

1 2	encounterDuration(tr, threshold, model = c("BBMM", "linear"), byburst = FALSE, timestepSize = 60) encounterDurationById(encounterDurationByBurst)

`tr`	The trajectory to analyze
`threshold`	The maximum distance at which an encounter is detected
`model`	The movement models for which to compute the encounter duration
`byburst`	If `TRUE`, the result contains durations for pairs of bursts. If `FALSE`, the result contains encounter durations between pairs of IDs.
`timestepSize`	If a movement model requires numerical integration in the time dimension, this is the size of each time step.
`encounterDurationByBurst`	The result of calling `encounterDuration` with `byburst=TRUE`.

Since the duration of encounters is a random variable in the Brownian bridge movement model, this function cannot give exact results there. Instead, it reports the expected duration of encounters in the BBMM.

If you already have the encounter duration between bursts and you also want the encounter duration between IDs, you should use encounterDurationById instead of calling encounterDuration again with different parameters. They give identical results, but the former is much faster since it does not recompute all relevant durations.

If byburst == FALSE, the result is a data.frame with one row for each interesting pair of bursts. A pair of bursts is interesting if they overlap in time, since otherwise the duration is always zero. The result contains the following fields:

`id1,id2`	The IDs of the bursts involved
`burst1,burst2`	The names of the bursts involved
	In addition there is one column for each model requested, named after the model. These columns are of type `difftime`, with unit `secs`. They contain the encounter duration according to that model.

If byburst == TRUE, the result is a 3 dimensional array, indexed by the two IDs and the movement model. The entries in the array are again of class difftime with unit secs.

bbtraj

data("vervet_monkeys", package="moveBB")

#ed <- encounterDuration(monkey.tr, 100, byburst=TRUE)
#barplot(ed)

#barplot(encounterDurationById(ed))

# This one has the same result, but needs to recompute everything
#barplot(encounterDuration(monkey.tr, 100))