Parameters for the Gaps Pattern

Circular bare gaps in vegetated ground.

Usage

pattern_gaps(
  n_gaps = 5,
  gap_radius = 10,
  gap_radius_sd = 0,
  radius_noise_fraction = 0,
  regular_gaps = FALSE
)

Arguments

n_gaps

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

gap_radius

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

gap_radius_sd

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

radius_noise_fraction

Numeric. Fraction of the gap 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 gap_radius_sd, which varies overall gap size.

regular_gaps

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

Value

A named "landscape_params" list containing the supplied parameters.

Details

This is the inverse of pattern_spots and therefore has no invert_landscape parameter.

See also

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

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_gaps	1 or more	5 to 9
gap_radius	1 or more	10 to 15, scales with size
gap_radius_sd	0 or more	0 to 2, scales with size
radius_noise_fraction	0 to 1	0 to 0.2
regular_gaps	TRUE or FALSE	TRUE or FALSE

Examples

# A single landscape, with fixed values
create_landscape("gaps", params = pattern_gaps(n_gaps = 5, gap_radius = 8))
#> Landscape: <unnamed> [pattern: gaps]
#> -----------------------------------------
#> 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 = TRUE, n_gaps = 5, gap_radius = 8, gap_radius_sd = 0, radius_noise_fraction = 0, regular_gaps = 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 = "gaps",
  params_list = list(
    gaps = pattern_gaps(
      n_gaps = c(4, 10),
      gap_radius = c(5, 10)
    )
  )
)
#> ✔ Successfully generated all 4 training landscapes
#> $gaps_1
#> Landscape: "gaps_1" [pattern: gaps]
#> -----------------------------------------
#> 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 = TRUE, n_gaps = 5, gap_radius = 6, gap_radius_sd = 1.5879343166016, radius_noise_fraction = 0.0886702800169587, regular_gaps = TRUE 
#> 
#> $gaps_2
#> Landscape: "gaps_2" [pattern: gaps]
#> -----------------------------------------
#> 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 = TRUE, n_gaps = 5, gap_radius = 7, gap_radius_sd = 1.62646044883877, radius_noise_fraction = 0.161126356152818, regular_gaps = TRUE 
#> 
#> $gaps_3
#> Landscape: "gaps_3" [pattern: gaps]
#> -----------------------------------------
#> 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 = TRUE, n_gaps = 8, gap_radius = 9, gap_radius_sd = 1.38248990988359, radius_noise_fraction = 0.141771729057655, regular_gaps = FALSE 
#> 
#> $gaps_4
#> Landscape: "gaps_4" [pattern: gaps]
#> -----------------------------------------
#> 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 = TRUE, n_gaps = 7, gap_radius = 9, gap_radius_sd = 1.52434144355357, radius_noise_fraction = 0.0125860714819282, regular_gaps = FALSE 
#> 

# A batch, mixing a fixed value with a range
create_landscapes(
  n = 4,
  patterns = "gaps",
  params_list = list(
    gaps = pattern_gaps(
      n_gaps = 6,
      gap_radius = c(5, 10)
    )
  )
)
#> ✔ Successfully generated all 4 training landscapes
#> $gaps_1
#> Landscape: "gaps_1" [pattern: gaps]
#> -----------------------------------------
#> 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 = TRUE, n_gaps = 6, gap_radius = 7, gap_radius_sd = 1.45131252333522, radius_noise_fraction = 0.0583874429110438, regular_gaps = FALSE 
#> 
#> $gaps_2
#> Landscape: "gaps_2" [pattern: gaps]
#> -----------------------------------------
#> 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 = TRUE, n_gaps = 6, gap_radius = 9, gap_radius_sd = 1.98492909874767, radius_noise_fraction = 0.098158588912338, regular_gaps = TRUE 
#> 
#> $gaps_3
#> Landscape: "gaps_3" [pattern: gaps]
#> -----------------------------------------
#> 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 = TRUE, n_gaps = 6, gap_radius = 8, gap_radius_sd = 1.77985197212547, radius_noise_fraction = 0.137208430189639, regular_gaps = TRUE 
#> 
#> $gaps_4
#> Landscape: "gaps_4" [pattern: gaps]
#> -----------------------------------------
#> 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 = TRUE, n_gaps = 6, gap_radius = 8, gap_radius_sd = 0.958843165077269, radius_noise_fraction = 0.161440896522254, regular_gaps = TRUE 
#>