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

knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>",
  fig.path = "man/figures/README-",
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topdowntimeratio

The goal of topdowntimeratio is to condense sequences of longitudinal GPS data into segments for ease of processing. This package was developed based on the method outlined in @Meratnia2004-mv, and as implemented in @McCool2022-yo.

Installation

The released version of topdowntimeratio can be installed from CRAN with:

install.packages("topdowntimeratio")

And the development version from GitHub with:

# install.packages("devtools")
devtools::install_github("daniellemccool/topdowntimeratio")

Example

Basic usage requires that your data has at least longitude and latitude coordinates as well as a timestamp and an id column. You can provide the names if they differ from entity_id, lon, lat and timestamp.

Here we generate a single segment

library(topdowntimeratio)
df <- data.frame(entity_id = c(1, 1, 1, 1),
                 lon = c(5, 5.01, 5.02, 5.05),
                 lat = c(32.01, 32.04, 32.06, 32.10),
                 timestamp = c(500, 600, 800, 2000))

res <- tdtr(df, n_segs = 1, group_col = NULL)

print(res)

Plot example, initial segment

plot(res$lon, res$lat)
segments(res$seg_start_lon, res$seg_start_lat, res$seg_end_lon, res$seg_end_lat)

Plot example, new segment at greatest distance

res <- tdtr(df, n_segs = 2, group_col = NULL)
plot(res$lon, res$lat)
segments(res$seg_start_lon, res$seg_start_lat, res$seg_end_lon, res$seg_end_lat)

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