quadrats: Quadrats

In spatialEco: Spatial Analysis and Modelling Utilities

Quadrats

Description

Creates quadrat polygons for sampling or analysis

Usage

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

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

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)

Value

an sf POLYGONS object with rotated polygon(s)

Author(s)

Jeffrey S. Evans <[e-mail]>

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))
 
   
# 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")
}
 

spatialEco documentation built on Nov. 18, 2023, 1:13 a.m.