getSegsExtra: Get Segments with calculated data

In daniellemccool/topdowntimeratio: Top-Down Time Ratio Segmentation for Coordinate Trajectories

Get Segments with calculated data

Description

This function calculates various segment-level metrics that require the raw data before returning a data.table with the segments and the calculated results. Calculates speed, bearing and radius of gyration information.

Usage

getSegsExtra(
  data,
  coord.type = c("coordinate", "distance", "both"),
  group = FALSE
)

Arguments

data	data.table returned from function /codetdtr
coord.type	return actual coordinates, relative distance, or both
group	Separate by group, default is FALSE

Value

data.table of segments, annotated with segment-level information on distance, mean and variance of immediate bearing difference, total bearing variance over the segment, mean, maximum and variance of calculated speed in meters per second, percentage of zero-speed entries, whether the segment consists of fewer than 3 locations, and the time-weighted radius of gyration.

Examples

df <- data.frame(entity_id = rep(1, 12),
   timestamp = c(1, 2, 4, 10, 14, 18, 20, 21, 24, 25, 28, 29),
   lon = c(5.1299311, 5.129979, 5.129597, 5.130028, 5.130555, 5.131083,
           5.132101, 5.132704, 5.133326, 5.133904, 5.134746, 5.135613),
   lat = c(52.092839, 52.092827, 52.092571, 52.092292, 52.092076, 52.091821,
           52.091420, 52.091219, 52.091343, 52.091651, 52.092138, 52.092698))
# First generate segments
res100 <- tdtr(df,
     group_col = NULL,
     max_error = 100)
# Then extract a data.table of segments
getSegsExtra(res100)

daniellemccool/topdowntimeratio documentation built on Sept. 27, 2022, 9:12 a.m.