MRG (version 0.3.21)

inspireID: Function to add inspireIDs to a multi-resolution grid, particular for European data sets

Description

Function to add inspireIDs to a multi-resolution grid, particular for European data sets

Usage

inspireID(himg, borders, cntrCol)

Arguments

himg

A multi-resolution grid, typically resulting from a call to multiResGrid

borders

A polygon object with borders and country codes for creation of INSPIRE coordinate IDs. This will typically be a NUTS-object that can be downloaded from GISCO: giscoR::gisco_get_nuts(nuts_level = 0, epsg = 3035).

cntrCol

The column with country information, if this is already present in the data

Details

The function will attempt to add an ID column following the principles of INSPIRE (Infrastructure for Spatial Information in Europe) if the multi-resolution grid has the inspire coordinate reference system (CRS=3035). See also https://epsg.io/3035 and https://inspire.ec.europa.eu/crs/3035.

The function will fail if the grid has any other CRS.

The function assumes that the grid is a correct multi-resolution grid without overlapping grid cells. If the column res is missing, the function will create this as the square root of the area of each grid cell. This will not work if the grid has already been clipped with coastal/country/region borders. The function tests if the number of different grid cell sizes is reasonable (maximum 10) and will issue a warning if it is higher.

The two first letters in the ID is usually the country code. This can be added in two different ways. Either by specifying the column with country code (argument: cntrCol) or by passing a polygon with country code information (argument: borders). It is assumed that this polygon has a column CNTR_CODE with the country codes, as typical in country-objects downloaded from GISCO.

However, it should be noted that grid cells on the borders will be associated to one of the countries - which in some cases could be unwanted. The method uses the st_nearest_feature functionality for associating a grid cell with a country. The example shows how this information can be added later, for users who want more control over the country association.

If neither borders nor country column is submitted, the function will use NA instead of country code in the ID.

Examples

# \donttest{
library(sf)
library(dplyr)
# These are SYNTHETIC agricultural FSS data 
data(ifs_dk) # Census data

# Create spatial data
ifg = fssgeo(ifs_dk, locAdj = "LL")

ress = c(1,5,10,20,40, 80, 160)*1000
# Gridding Utilized agricultural area (UAA)
ifl = gridData(ifg, "UAA",res = ress)

# Create a multi-resolution grid only with farm number as confidentiality rule, then plot results
himg = multiResGrid(ifl, checkReliability = FALSE, suppresslim = 0)

himg = inspireID(himg) 

# It is easy to modify the country information afterwards
if (require(giscoR)) {
  borders = gisco_get_nuts(nuts_level = 0, epsg = 3035)
  himg1 = inspireID(himg, borders)
  himg2 = st_join(himg, borders %>% select(CNTR_CODE), join = st_nearest_feature)
  himg2 = inspireID(himg2, cntrCol = "CNTR_CODE")
# The border issues cause some grid cell to be classified as German, although 
# all data is from Denmark 
  table(substr(himg1$ID, 1, 2))
}
# }