GeoOutlier: Spatial outlier detection

In GeoModels: Procedures for Gaussian and Non Gaussian Geostatistical (Large) Data Analysis

Spatial outlier detection

Description

Detects outliers in a univariate purely spatial data set using the selected local procedure. Space-time and bivariate outlier detection are not currently implemented.

Usage

GeoOutlier(data, coordx, coordy=NULL,coordz=NULL, coordt=NULL, coordx_dyn=NULL, 
 distance="Eucl", grid=FALSE, neighb=10,alpha=0.001,
 method="Z-Median", radius=1, bivariate=FALSE,X=NULL)

Arguments

data	A numeric vector containing a single spatial realization, or a matrix representing a single spatial realization on a regular grid. Space-time data are not currently supported.
coordx	A numeric (d \times 2)-matrix or (d \times 3)-matrix Coordinates on a sphere for a fixed radius radius are passed in lon/lat format expressed in decimal degrees.
coordy	A numeric vector giving 1-dimension of spatial coordinates; Optional argument, the default is NULL.
coordz	A numeric vector giving 1-dimension of spatial coordinates; Optional argument, the default is NULL.
coordt	Retained for API compatibility. GeoOutlier is currently implemented only for purely spatial data and rejects space-time input.
coordx_dyn	Retained for API compatibility. Dynamic space-time coordinates are not currently implemented.
distance	String; the name of the spatial distance. The default is Eucl, the Euclidean distance. See GeoFit for details.
grid	Logical; if FALSE (the default), the data are interpreted as a spatial realization on explicit, possibly non-equispaced, spatial sites.
neighb	Numeric; an optional positive integer indicating the order of neighborhoodused for Z-Median algorithm.
alpha	Numeric; a numeric value between 0 and 1 used for Z-Median algorithm.
method	String; The name of the algorithm for detecting spatial ouliers. Default is Z-median proposed in Chen et al. (2008)
radius	Numeric; a value indicating the radius of the sphere when using the great circle distance. Default value is 1.
bivariate	Retained for API compatibility. Bivariate outlier detection is not currently implemented and TRUE is rejected.
X	Numeric; an optional matrix of spatial covariates with one row per observation.

Value

Returns a matrix containing the detected spatial outliers

Three-dimensional coordinates

Purely spatial irregular coordinates may be supplied as an N \times 3 matrix or as separate coordx, coordy, and coordz vectors. Three-dimensional coordinates require distance = "Eucl". Space-time and bivariate outlier detection are not implemented.

Author(s)

Moreno Bevilacqua, [e-mail],https://sites.google.com/view/moreno-bevilacqua/home, Víctor Morales Oñate, [e-mail], https://sites.google.com/site/moralesonatevictor/, Christian Caamaño-Carrillo, [e-mail],https://www.researchgate.net/profile/Christian-Caamano

References

Chen D, Lu C, Kou Y, Chen F (2008) On detecting spatial outliers. Geoinformatica 12:455–475

Bevilacqua M., Caamaño C., Arellano-Valle R. B., Camilo Gomez C. (2022) A class of random fields with two-piece marginal distributions for modeling point-referenced data with spatial outliers. Test 10.1007/s11749-021-00797-5

GeoModels documentation built on Sept. 23, 2026, 5:07 p.m.