spatialPointsCellCodes: Add cell identifiers to SpatialPoints as in INSPIRE Specification

Description

spatialPointsCellCodes returns a SpatialPointsDataFrame with identifiers (CellCode and CellNum) for each point as in INSPIRE Specification on Geographical Grid Systems.

Usage

spatialPointsCellCodes(points, dim = 1000, layers = 1)

Value

A "SpatialPointsDataFrame" containing all the points given. For each point a cellCode and cellNum identify the cell to which the point belongs.

CellCode is a text string, composed of cell size and cell coordinates. Cell codes start with a cell size prefix. The cell size is denoted in meter (m) for cell sizes below 1000 m and kilometer (km) for cell sizes from 1000 m and above.

The cellNum is a sequence identifying the different partitions of the main cell in which the point resides.

Arguments

points: object of class "SpatialPoints" or "SpatialPointsDataFrame".
dim: a single integer specifying the initial cell sizes, defaults to 1km.
layers: a single integer specifying the number of divisions of the initial cells, defaults to 1.

Details

INSPIRE coding system for point identifiers
The objective of the coding system is to generate unique identifiers for each point, for any of the recommended resolutions.
The cellCode is a text string, composed of cell size and cell coordinates. Cell codes start with a cell size prefix. The cell size is denoted in meter (m) for cell sizes below 1000 m and kilometre (km) for cell sizes from 1000 m and above.
Examples: a 100 meter cell has an identifier starting with “100m”, the identifier of a 10000 meter cell starts with “10km”.
The coordinate part of the cell code reflects the distance of the lower left grid cell corner from the false origin of the CRS. In order to reduce the length of the string, Easting (E) and Northing (N) values are divided by 10n (n is the number of zeros in the cell size value). Example for a cell size of 10000 meters: The number of zeros in the cell size value is 4. The resulting divider for Easting and Northing values is 104 = 10000.
The cellNum is a sequence of concatenated integers identifying all the hierarchical partitions of the main cell in which the point resides. For instance, the cellNum of the top right cell would be 416 (fourth in first partition, sixteenth in second partition)
Hyerarchical CellNums

The input object must be projected and units should be in 'meters' because the system uses the INSPIRE coding system.

Examples

Run this code

data("BarcelonaPop")
BarcelonaPop.IDs<-spatialPointsCellCodes(BarcelonaPop)
BarcelonaPop.IDs.10km<-spatialPointsCellCodes(BarcelonaPop, 10000, 3)

if (FALSE) {
## spatial object not projected
sp.not.projected<-spTransform(CharlestonPop,CRS("+proj=longlat +datum=NAD27"))
is.projected(sp.not.projected)
spatialPointsCellCodes(sp.not.projected)
}

Run the code above in your browser using DataLab