R/fssi2d.R

In SPSL: Site Percolation on Square Lattices (SPSL)

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# Function: 
# fssi2d() and fssi3d() functions calculates the relative 
# frequency distribution of isotropic 2D & 3D clusters 
# with Moore d-neighborhood.
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# Arguments:
# n - sample size;
# x - linear dimension of the percolation lattice; 
# p0 - relative fraction of accessible sites
#      (occupation probability) for percolation lattice;
# p1, p2 - p1 value, weighted by 2D & 3D d-neighborhood;
# set - vector of linear indexes of starting sites subset;
# all - trigger "Do we mark all starting sites or only accessible?";
# shape - vector of shape parameters of beta-distributed random variables, 
#         weighting the percolation lattice sites.
# Value:
# rfq - matrix of relative frequencies for sites of the percolation lattice.
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fssi2d <- function(n=1000, 
                   x=33, p0=0.5, p1=p0/2,
                   set=(x^2+1)/2, all=TRUE,
                   shape=c(1,1)) {
  rfq <- array(0, dim=rep(x, times=2))
  for (i in seq(n))
    rfq <- rfq + (ssi2d(x, p0, p1, set, all, shape) > 1)
  return(rfq/n)
}
fssi3d <- function(n=1000,
                   x=33, p0=0.2, p1=p0/2, p2=p0/3, 
                   set=(x^3+1)/2, all=TRUE,
                   shape=c(1,1)) {
  rfq <- array(0, dim=rep(x, times=3))
  for (i in seq(n))
    rfq <- rfq + (ssi3d(x, p0, p1, p2, set, all, shape) > 1)
  return(rfq/n)
}