SpatGC (version 0.1.0)

Poislat: Fit Poisson Spatial Model

Description

This function fits a Poisson spatial model (including zero-inflated and gamma Poisson variations) to a given dataset using the INLA package. It constructs the formula based on the provided covariate data and ID variables, and fits the model using the specified adjacency matrix (`W`) or a shapefile of the study region.

Usage

Poislat(
  Y,
  ID,
  W = NULL,
  shapefile = NULL,
  covariate = NULL,
  family = c("gpoisson", "poisson", "zeroinflatedpoisson0", "zeroinflatedpoisson1")
)

Value

An object of class "inla" representing the fitted Poisson spatial model. The object contains model estimates, diagnostics, and other results.

Arguments

Y

Vector of response variables (counts).

ID

Vector of indexes of regions (spatial units).

W

Optional adjacency matrix representing spatial connections between regions. If not provided, it can be generated from a shapefile using the `shapefile` argument.

shapefile

Optional shapefile representing the study region. If provided, the adjacency matrix (`W`) will be calculated from the shapefile.

covariate

Optional matrix of covariates. If not provided, the function assumes the model is intercept-only.

family

The family of Poisson models to use. Options are "gpoisson", "poisson", "zeroinflatedpoisson0", and "zeroinflatedpoisson1".

Examples

# \donttest{
  # Generate data from the GC spatial regression model with lattice spatial dependency
  W <- rAdj(500) # Generate a random adjacency matrix
  DDl <- rGClat(n = 200, alpha = 1, beta0 = 0.3, beta = c(-0.5, 0.5),
  W = W, spatial = "lattice", V = 1)

  # Prepare the data
  Y <- DDl$y
  covariate <- DDl$covariate
  ID <- DDl$ID

  # Fit the spatial Poisson model
  ResultPoisson <- Poislat(Y = Y, ID = ID, covariate = covariate, W = W, family = "poisson")

  # Summary of the model fit
  summary(ResultPoisson)
# }