Permutation based Getis-Ord Gi or Gi* statistics for spatial hots pot analysis

Source: R/local.R

Calculate permutation based p-value for Getis-Ord Gi or Gi* statistics.

PermutationGi(
  x,
  W,
  gstar = TRUE,
  n = 999,
  seed = 1,
  alternative = c("two.sided", "less", "greater"),
  p.adjust.method = "BH",
  return.permutation = FALSE,
  condition = 0
)

Arguments

x

A numerical vector.

W

A weight matrix across all observations, i.e inverse of a pairwise distance matrix.

gstar

Whether to calculate the Gi* statistics, default is TRUE.

n

The number of permutations to be conducted, set to 999 by default.

seed

Random seed used. Default is 1.

alternative

Alternative hypothesis used, default is two.sided.

p.adjust.method

Method used for multiple comparisons correction, default is BH. See p.adjust.

return.permutation

Return permutations. Default is FALSE.

condition

Value under null hypothesis to compare with, default is 0.

Value

A list containing the following:

  • Gi, Gi or Gi* statistics.

  • p.val, permutation based p-value.

  • p.adj, adjusted p-values.

  • return.permutation, permutation used if returned.

  • params, parameters used to calculate local Moran's I.

Examples

{
data.use <- quakes[1:100,]
W <- 1/as.matrix(dist(data.use[,1:2]))
diag(W) <- 0
res <- PermutationGi(data.use[,3], W)
}