spatialEco (version 2.0-2)

quadrats: Quadrats

Description

Creates quadrat polygons for sampling or analysis

Usage

quadrats(x, s = 250, n = 100, r = NULL, sp = FALSE)

Value

an sf POLYGONS object with rotated polygon(s)

Arguments

x

An sf POLYGONS object defining extent

s

Radius defining single or range of sizes of quadrats

n

Number of quadrats

r

A rotation factor for random rotation, default is NULL

sp

(FALSE | TRUE) Output sp class object

Author

Jeffrey S. Evans <[e-mail]>

Details

The radius (s) parameter can be a single value or a range of values, representing a randomization range of resulting quadrat sizes. The rotation (r) parameter can also be used to defined a fixed rotation or random range of quadrat rotations. You can specify each of these parameters using an explicit vector that will be sampled eg., seq(100,300,0.5)

Examples

library(sf)
library(terra) 

# read meuse data and create convex hull 
if (require(sp, quietly = TRUE)) {
  data(meuse, package = "sp")
  meuse <- st_as_sf(meuse, coords = c("x", "y"), crs = 28992, agr = "constant")
  e <- st_convex_hull(st_union(meuse))

 # Fixed size 250 and no rotation 
 s <- quadrats(e, s = 250, n = 10)
   plot(st_geometry(s))
 
# \donttest{   
# Variable sizes 100-300 and rotation of 0-45 degrees
s <- quadrats(e, s = c(100,300), n = 10, r = c(0,45))
  plot(st_geometry(s))
 
# Variable sizes 100-300 and no rotation 
s <- quadrats(e, s = c(100,300), n = 10)
  plot(st_geometry(s))
# }   

} else { 
  cat("Please install sp package to run example", "\n")
}