Parameters for the Spots Pattern

Circular vegetation patches on bare ground.

Usage

pattern_spots(
  n_spots = 5,
  spot_radius = 10,
  spot_radius_sd = 0,
  radius_noise_fraction = 0,
  regular_spots = FALSE,
  invert_landscape = FALSE
)

Arguments

n_spots

Integer. Number of spots (default: 5). Regular placement may reduce this number if the landscape cannot accommodate the requested count with the given spot_radius.

spot_radius

Numeric. Mean radius of each spot in pixels (default: 10). Must be positive and smaller than landscape dimensions.

spot_radius_sd

Numeric. Standard deviation of normally sampled spot radii (default: 0, no variation).

radius_noise_fraction

Numeric. Fraction of the spot radius with a gradual edge transition (0-1). Zero gives sharp edges; 1 applies probabilistic cell inclusion across the full radius. For example, 0.2 applies the transition to the outer 20%. This is independent of spot_radius_sd, which varies overall spot size.

regular_spots

Logical. Arrange spots on a hexagonal grid using k-means clustering rather than placing them randomly (default: FALSE).

invert_landscape

Logical. Create bare patches in vegetated ground, equivalent to the "gaps" pattern (default: FALSE).

Value

A named "landscape_params" list containing the supplied parameters.

See also

Other landscape creation: create_landscape(), create_landscapes(), pattern_bands(), pattern_bare(), pattern_clustered(), pattern_dense(), pattern_diffuse(), pattern_fingers(), pattern_gaps(), pattern_labyrinth(), pattern_random(), pattern_sharp()

Valid values and batch sampling

A single value fixes a parameter. A length-2 vector is a range, sampled once per landscape by create_landscapes and rejected by create_landscape. The table below shows for each parameter:

valid values that create_landscape accepts, and sampled ranges that create_landscapes draws from once per landscape for any parameter left unset. The defaults shown in Usage therefore apply to create_landscape only. Ranges that scale with landscape size are shown for the default 100 by 100.

Parameter	Valid	Sampled
n_spots	1 or more	5 to 9
spot_radius	1 or more	10 to 15, scales with size
spot_radius_sd	0 or more	0 to 2, scales with size
radius_noise_fraction	0 to 1	0 to 0.2
regular_spots	TRUE or FALSE	TRUE or FALSE
invert_landscape	TRUE or FALSE	always FALSE

Examples

# A single landscape, with fixed values
create_landscape("spots", params = pattern_spots(n_spots = 15))
#> Landscape: <unnamed> [pattern: spots]
#> -----------------------------------------
#> Dimensions: 100x100 (10000 cells)
#> Resolution: 1.0x1.0
#> Extent    : xmin=0.0, xmax=100.0, ymin=0.0, ymax=100.0
#> Values    : min=0.0, max=1.0
#> Parameters: width = 100, height = 100, invert_landscape = FALSE, n_spots = 15, spot_radius = 10, spot_radius_sd = 0, radius_noise_fraction = 0, regular_spots = FALSE 

# A batch, with parameters drawn from ranges once per landscape.
# Parameters left unset vary too, over their default ranges
create_landscapes(
  n = 4,
  patterns = "spots",
  params_list = list(
    spots = pattern_spots(
      n_spots = c(5, 15),
      spot_radius = c(4, 8)
    )
  )
)
#> ✔ Successfully generated all 4 training landscapes
#> $spots_1
#> Landscape: "spots_1" [pattern: spots]
#> -----------------------------------------
#> Dimensions: 100x100 (10000 cells)
#> Resolution: 1.0x1.0
#> Extent    : xmin=0.0, xmax=100.0, ymin=0.0, ymax=100.0
#> Values    : min=0.0, max=1.0
#> Parameters: width = 100, height = 100, invert_landscape = FALSE, n_spots = 12, spot_radius = 8, spot_radius_sd = 0.556843919679523, radius_noise_fraction = 0.127978959167376, regular_spots = TRUE 
#> 
#> $spots_2
#> Landscape: "spots_2" [pattern: spots]
#> -----------------------------------------
#> Dimensions: 100x100 (10000 cells)
#> Resolution: 1.0x1.0
#> Extent    : xmin=0.0, xmax=100.0, ymin=0.0, ymax=100.0
#> Values    : min=0.0, max=1.0
#> Parameters: width = 100, height = 100, invert_landscape = FALSE, n_spots = 13, spot_radius = 7, spot_radius_sd = 1.88310010032728, radius_noise_fraction = 0.088484320230782, regular_spots = FALSE 
#> 
#> $spots_3
#> Landscape: "spots_3" [pattern: spots]
#> -----------------------------------------
#> Dimensions: 100x100 (10000 cells)
#> Resolution: 1.0x1.0
#> Extent    : xmin=0.0, xmax=100.0, ymin=0.0, ymax=100.0
#> Values    : min=0.0, max=1.0
#> Parameters: width = 100, height = 100, invert_landscape = FALSE, n_spots = 11, spot_radius = 4, spot_radius_sd = 0.00559949595481157, radius_noise_fraction = 0.0810569220222533, regular_spots = FALSE 
#> 
#> $spots_4
#> Landscape: "spots_4" [pattern: spots]
#> -----------------------------------------
#> Dimensions: 100x100 (10000 cells)
#> Resolution: 1.0x1.0
#> Extent    : xmin=0.0, xmax=100.0, ymin=0.0, ymax=100.0
#> Values    : min=0.0, max=1.0
#> Parameters: width = 100, height = 100, invert_landscape = FALSE, n_spots = 13, spot_radius = 4, spot_radius_sd = 1.20245855813846, radius_noise_fraction = 0.166129577020183, regular_spots = FALSE 
#> 

# A batch, mixing a fixed value with a range
create_landscapes(
  n = 4,
  patterns = "spots",
  params_list = list(
    spots = pattern_spots(
      n_spots = 10,
      spot_radius = c(4, 8)
    )
  )
)
#> ✔ Successfully generated all 4 training landscapes
#> $spots_1
#> Landscape: "spots_1" [pattern: spots]
#> -----------------------------------------
#> Dimensions: 100x100 (10000 cells)
#> Resolution: 1.0x1.0
#> Extent    : xmin=0.0, xmax=100.0, ymin=0.0, ymax=100.0
#> Values    : min=0.0, max=1.0
#> Parameters: width = 100, height = 100, invert_landscape = FALSE, n_spots = 10, spot_radius = 8, spot_radius_sd = 0.224441807717085, radius_noise_fraction = 0.128724273247644, regular_spots = FALSE 
#> 
#> $spots_2
#> Landscape: "spots_2" [pattern: spots]
#> -----------------------------------------
#> Dimensions: 100x100 (10000 cells)
#> Resolution: 1.0x1.0
#> Extent    : xmin=0.0, xmax=100.0, ymin=0.0, ymax=100.0
#> Values    : min=0.0, max=1.0
#> Parameters: width = 100, height = 100, invert_landscape = FALSE, n_spots = 10, spot_radius = 4, spot_radius_sd = 0.11422164645046, radius_noise_fraction = 0.187016865704209, regular_spots = FALSE 
#> 
#> $spots_3
#> Landscape: "spots_3" [pattern: spots]
#> -----------------------------------------
#> Dimensions: 100x100 (10000 cells)
#> Resolution: 1.0x1.0
#> Extent    : xmin=0.0, xmax=100.0, ymin=0.0, ymax=100.0
#> Values    : min=0.0, max=1.0
#> Parameters: width = 100, height = 100, invert_landscape = FALSE, n_spots = 10, spot_radius = 8, spot_radius_sd = 1.4696095995605, radius_noise_fraction = 0.130052016023546, regular_spots = FALSE 
#> 
#> $spots_4
#> Landscape: "spots_4" [pattern: spots]
#> -----------------------------------------
#> Dimensions: 100x100 (10000 cells)
#> Resolution: 1.0x1.0
#> Extent    : xmin=0.0, xmax=100.0, ymin=0.0, ymax=100.0
#> Values    : min=0.0, max=1.0
#> Parameters: width = 100, height = 100, invert_landscape = FALSE, n_spots = 10, spot_radius = 8, spot_radius_sd = 0.716070289723575, radius_noise_fraction = 0.143712487304583, regular_spots = FALSE 
#>