random_points: Generate random points

In amt: Animal Movement Tools

Generate random points

Description

Functions to generate random points within an animals home range. This is usually the first step for investigating habitat selection via Resource Selection Functions (RSF).

Usage

random_points(x, ...)

## S3 method for class 'hr'
random_points(x, n = 100, type = "random", presence = NULL, ...)

## S3 method for class 'sf'
random_points(x, n = 100, type = "random", presence = NULL, ...)

## S3 method for class 'track_xy'
random_points(x, level = 1, hr = "mcp", n = nrow(x) * 10, type = "random", ...)

Arguments

x	[track_xy, track_xyt] A track created with make_track.
...	⁠[any]⁠ None implemented.
n	⁠[integer(1)]⁠ The number of random points.
type	⁠[character(1)]⁠ Argument passed to sf::st_sample. The default is random.
presence	⁠[track]⁠ The presence points, that will be added to the result.
level	⁠[numeric(1)]⁠ Home-range level of the minimum convex polygon, used for generating the background samples.
hr	⁠[character(1)]⁠ The home range estimator to be used. Currently only MCP is implemented.

Value

A tibble with the observed and random points and a new column case_ that indicates if a point is observed (case_ = TRUE) or random (⁠case_ TRUE⁠).

Note

For objects of class track_xyt the timestamp (t_) is lost.

Examples

data(deer)

# track_xyt ---------------------------------------------------------------
# Default settings
rp1 <- random_points(deer)

plot(rp1)

# Ten random points for each observed point
rp <- random_points(deer, n = nrow(deer) * 10)
plot(rp)

# Within a home range -----------------------------------------------------
hr <- hr_mcp(deer, level = 1)

# 100 random point within the home range
rp <- random_points(hr, n = 100)
plot(rp)

# 100 regular point within the home range
rp <- random_points(hr, n = 100, type = "regular")
plot(rp)
# 100 hexagonal point within the home range
rp <- random_points(hr, n = 100, type = "hexagonal")
plot(rp)

amt documentation built on June 25, 2024, 1:14 a.m.