# dneigh: Construct neighbours list In babaknaimi/elsa: Entropy-Based Local Indicator of Spatial Association

 dneigh R Documentation

## Construct neighbours list

### Description

This function identifies the neighbours features (points or polygons) given the specified distance (in kilometer for geographic coordinates, i.e., if longlat=TRUE; and in the map unit for projected datasets, i.e., if longlat = FALSE) and builds a list of neighbours.

The neighd function returns a list including distance of each feature to neighbourhood locations.

### Usage

``````dneigh(x,d1,d2,longlat,method,...)

neighd(x,d1,d2,longlat,...)
``````

### Arguments

 `x` a SpatialPoints, or SpatialPolygons or a matrix (or data.frame) of point coordinates or a SpatialPoints object `d1` lower local distance bound (if longlat = TRUE, in kilometer; otherwise in the spatial unit of the dataset, e.g., meter) `d2` upper local distance bound (if longlat = TRUE, in kilometer; otherwise in the spatial unit of the dataset, e.g., meter) `longlat` TRUE if point coordinates are longitude-latitude `method` if x is SpatialPolygons, specifies the method to identify the neighbour polygons; see details `...` additional arguments; see details

### Details

The function is mostly based on `dnearneigh` (for points), and `poly2nb` (for polygons), implemented in the spdep package by Roger Bivand.

When `x` is SpatialPolygons, there is two methods (can be specified through `method`) to identify the neighbour polygons. The default method ('bound') seeks the polygons that has one or more points in their boundaries within the specified distance (`d`), while the method 'centroid' considers any polygon with a centriod within the given distance.

One additional argument is queen (default is TRUE), can beused only when x is SpatialPolygons, and method='bound', if TRUE, a single shared boundary point meets the contiguity condition, if FALSE, more than one shared point is required.

`neighd` for SpatialPolygons returns distances of each polygon to centroids of neighbor polygons.

### Value

An object of class `neighbours`

### Author(s)

Babak Naimi naimi.b@gmail.com

### References

Naimi, B., Hamm, N. A., Groen, T. A., Skidmore, A. K., Toxopeus, A. G., & Alibakhshi, S. (2019). ELSA: Entropy-based local indicator of spatial association. Spatial statistics, 29, 66-88.

### Examples

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babaknaimi/elsa documentation built on Jan. 28, 2024, 10 a.m.