Calculate fractal dimension using the cube counting method
Arguments
- data
An object of class RasterLayer or mesh3d.
- lvec
Vector of scales to use for calculation (i.e. cube sizes).
- plot
Planar representation of cubes superimposed on 3D mesh or DEM for visualizing
lvec
. Default = FALSE.- keep_data
Logical. Keep calculation data? Default = TRUE.
- scale
Logical. Rescale height values to the extent? Only relevant for RasterLayer objects. (Defaults to FALSE).
Details
This function calculates fractal dimension using the cube counting method.
If lvec
is not specified, a default based on resolution and extent will be used.
Based on lvec, cubes of different sizes are defined and the function counts mesh points that fall within each cube.
It is recommended to specify the maximum value of lvec
so that the largest box encapsulates the entire object.
The smallest scale included in lvec
should not be smaller than the resolution of your object.
Examples
fd_cubes(mcap, keep_data = TRUE, plot = TRUE)
#> lvec is set to c(0.053, 0.106, 0.212, 0.423).
#> $D
#> [1] 2.315246
#>
#> $lvec
#> [1] 0.42329634 0.21164817 0.10582408 0.05291204
#>
#> $data
#> l n
#> 1 0.42329634 1
#> 2 0.21164817 8
#> 3 0.10582408 31
#> 4 0.05291204 134
#>
#> $method
#> [1] "cubes"
#>
fd_cubes(mcap, lvec = c(0.05, 0.1, 0.25, 0.5), plot = TRUE)
#> [1] 2.200376
dem <- dem_crop(horseshoe, x0 = -469, y0 = 1267, L = 2, plot = TRUE)
fd_cubes(dem, plot = TRUE, keep_data = TRUE)
#> lvec is set to c(0.016, 0.031, 0.063, 0.125, 0.25, 0.5, 1, 2).
#> $D
#> [1] 2.06335
#>
#> $lvec
#> [1] 2.000000 1.000000 0.500000 0.250000 0.125000 0.062500 0.031250 0.015625
#>
#> $data
#> l n
#> 1 2.000000 1
#> 2 1.000000 7
#> 3 0.500000 33
#> 4 0.250000 157
#> 5 0.125000 626
#> 6 0.062500 2405
#> 7 0.031250 8254
#> 8 0.015625 23742
#>
#> $method
#> [1] "cubes"
#>
fd_cubes(dem, plot = TRUE, keep_data = TRUE, scale = TRUE)
#> lvec is set to c(0.016, 0.031, 0.063, 0.126, 0.251, 0.502, 1.005, 2.01).
#> $D
#> [1] 2.099471
#>
#> $lvec
#> [1] 2.01000000 1.00500000 0.50250000 0.25125000 0.12562500 0.06281250 0.03140625
#> [8] 0.01570312
#>
#> $data
#> l n
#> 1 2.01000000 1
#> 2 1.00500000 8
#> 3 0.50250000 47
#> 4 0.25125000 218
#> 5 0.12562500 940
#> 6 0.06281250 3530
#> 7 0.03140625 11244
#> 8 0.01570312 27610
#>
#> $method
#> [1] "cubes"
#>