spatial causality test

Usage

# S4 method for class 'sf'
sc.test(
  data,
  cause,
  effect,
  k,
  block = 3,
  boot = 399,
  seed = 42L,
  base = 2,
  lib = NULL,
  pred = NULL,
  threads = detectThreads(),
  detrend = TRUE,
  normalize = FALSE,
  progressbar = FALSE,
  nb = NULL
)

# S4 method for class 'SpatRaster'
sc.test(
  data,
  cause,
  effect,
  k,
  block = 3,
  boot = 399,
  seed = 42L,
  base = 2,
  lib = NULL,
  pred = NULL,
  threads = detectThreads(),
  detrend = TRUE,
  normalize = FALSE,
  progressbar = FALSE,
  grid.coord = TRUE,
  embed.direction = 0
)

Arguments

data: observation data.
cause: name of causal variable.
effect: name of effect variable.
k: (optional) number of nearest neighbors used in symbolization.
block: (optional) number of blocks used in spatial block bootstrap.
boot: (optional) number of bootstraps to perform.
seed: (optional) random seed.
base: (optional) logarithm base.
lib: (optional) libraries indices (input requirement same as libsizes).
pred: (optional) predictions indices (input requirement same as libsizes).
threads: (optional) number of threads to use.
detrend: (optional) whether to remove the linear trend.
normalize: (optional) whether to normalize the result.
progressbar: (optional) whether to show the progress bar.
nb: (optional) neighbours list.
grid.coord: (optional) whether to detrend using cell center coordinates (TRUE) or row/column numbers (FALSE).
embed.direction: (optional) direction selector for embeddings (0 returns all directions, 1-8 correspond to NW, N, NE, W, E, SW, S, SE).

Value

A list

sc: statistic for spatial causality
varname: names of causal and effect variables

References

Herrera, M., Mur, J., Ruiz, M., 2016. Detecting causal relationships between spatial processes. Papers in Regional Science 95, 577–595.

Examples

columbus = sf::read_sf(system.file("case/columbus.gpkg",package="spEDM"))
# \donttest{
spEDM::sc.test(columbus,"hoval","crime",k = 15)
#> spatial causality test
#> hoval -> crime: statistic = 1.114, p value = 0.549
#> crime -> hoval: statistic = 1.555, p value = 0.008
# }