mergingCycle: Merging Cycle

In stopdetection: Stop Detection in Timestamped Trajectory Data using Spatiotemporal Clustering

Merging Cycle

Description

Runs the stop and merging cycle until no changes are seen or until the max number of merges are met.

Usage

mergingCycle(
  res,
  max_merges = Inf,
  thetaD = 200,
  small_track_action = "merge",
  ...
)

Arguments

res	Results data.table from stopFinder containing columns timestamp, longitude, latitude and state
max_merges	integer of maximum number of merges to perform
thetaD	how many meters away may stops be and still be merged
small_track_action	one of "merge" or "exclude" for short tracks
...	additional optional arguments passed to moveMerger including max_locs, max_time and max_dist

Value

Modifies res data.table by reference

Examples

# Load data
library(data.table)
data(loc_data_2019); setDT(loc_data_2019)
# Find initial set of stops
stopFinder(loc_data_2019, thetaD = 200, thetaT = 300)
# This selection contains two short tracks to eliminate and two stops to merge
example <- copy(loc_data_2019[state_id %between% c(1, 11)])
events_pre_merge <- returnStateEvents(example)
# Perform the merging
mergingCycle(example, thetaD = 200, small_track_action = "exclude", max_locs = Inf)
events_post_merge <- returnStateEvents(example)
# From 11 states to 8 states
events_pre_merge[, .(state_id, state, meanlat, meanlon, n_locations)]
events_post_merge[, .(state_id, state, meanlat, meanlon, n_locations)]

stopdetection documentation built on April 18, 2023, 5:06 p.m.