Ising model for spatial data — kinetic

Performs simulations based on the given parameters of the Ising model

kinetic_ising(
  x,
  B,
  J,
  updates = 1,
  iter,
  rule = "glauber",
  inertia = 0,
  version = 1,
  progress = FALSE
)

Arguments

x: SpatRaster or matrix containing two values: -1 and 1
B: External pressure (positive or negative): it tries to align cells' values with its sign
J: Strength of the local autocorrelation tendency (always positive): it tries to align signs of neighboring cells
updates: Specifies how many sets of iterations are performed on the input object. The output of this function has as many layers as the updates value.
iter: Specifies how many iterations are performed on the input object. By default it equals to the number of values in the input object.
rule: IM temporal evolution rule: either "glauber" (default) or "metropolis"
inertia: Represents the modification of the algorithm aimed at suppressing the salt-and-pepper noise of the focus category present when simulating evolution of a coarse-textured pattern. With Q > 0, small patches of the focus category are not generated, thus eliminating the salt-and-pepper noise of the focus category
version: By default, 1, the x object is converted into a matrix (fast, but can be memory consuming); version = 2 has a lower RAM impact, but is much slower
progress: TRUE/FALSE

Value

Object of the same class as x with the number of layers specified by updates

References

Ising, E., 1924. Beitrag zur theorie des ferro-und paramagnetismus. Ph.D. thesis, Grefe & Tiedemann.

Onsager, L., 1944. Crystal statistics. I. A two-dimensional model with an order-disorder transition. Physical Review 65 (3-4), 117.

Brush, S. G., 1967. History of the Lenz-Ising model. Reviews of modern physics 39 (4), 883.

Cipra, B. A., 1987. An introduction to the Ising model. The American Mathematical Monthly 94 (10), 937–959.

Examples

data(r_start, package = "spatialising")
ts1 = kinetic_ising(r_start, B = -0.3, J = 0.7)
ts10 = kinetic_ising(r_start, B = -0.3, J = 0.7, updates = 10)

# \donttest{
  r1 = terra::rast(system.file("raster/r_start.tif", package = "spatialising"))
  terra::plot(r1)

  r2 = kinetic_ising(r1, B = -0.3, J = 0.7)
  terra::plot(r2)


  library(terra)
  ri1 = kinetic_ising(r1, B = -0.3, J = 0.7, updates = 9)
  plot(ri1)


  ri2 = kinetic_ising(r1, B = 0.3, J = 0.7, updates = 9)
  plot(ri2)


  ri3 = kinetic_ising(r1, B = -0.3, J = 0.4, updates = 9)
  plot(ri3)

# }