Make SpatialLines object from two SpatialPoints objects

Source: R/plotting-helpers.R

The primary conceived usage of this is to draw arrows following the trajectories of agents.

makeLines(from, to)

Arguments

from

Starting spatial coordinates (SpatialPointsDataFrame).

to

Ending spatial coordinates (SpatialPointsDataFrame).

Value

A SpatialLines object. When this object is used within a Plot call and the length argument is specified, then arrow heads will be drawn. See examples.

Author

Eliot McIntire

Examples

library(terra)
# Make 2 objects
caribou1 <- terra::vect(cbind(x = stats::runif(10, -50, 50),
                              y = stats::runif(10, -50, 50)))
caribou2 <- terra::vect(cbind(x = stats::runif(10, -50, 50),
                              y = stats::runif(10, -50, 50)))

caribouTraj <- makeLines(caribou1, caribou2)

if (interactive())
  Plot(caribouTraj, length = 0.1) # shows arrows

# or  to a previous Plot
files <- dir(system.file("maps", package = "quickPlot"), full.names = TRUE, pattern = "tif")
maps <- lapply(files, terra::rast)
names(maps) <- lapply(maps, names)

caribouTraj <- makeLines(caribou1, caribou2)

if (interactive()) {
  clearPlot()
  Plot(maps$DEM)
  Plot(caribouTraj, addTo = "maps$DEM", length = 0.1)
}