These are functions to work with geographical data. To determine coordinates based on a location (or vice versa), use geocode() / reverse_geocode().

get_map(maptype = "postcodes4")

add_map(data, maptype = NULL, by = NULL, crop_certe = TRUE)

is.sf(sf_data)

as.sf(data)

crop_certe(sf_data)

filter_geolocation(sf_data, ...)

filter_sf(sf_data, xmin = NULL, xmax = NULL, ymin = NULL, ymax = NULL)

convert_to_degrees_CRS4326(sf_data)

convert_to_metre_CRS28992(sf_data)

degrees_to_sf(longitudes, latitudes, crs = 28992)

latitude(sf_data)

longitude(sf_data)

Arguments

maptype

type of geometric data, must be one of: "gemeenten", "ggdregios", "nuts3", "postcodes2", "postcodes3", "postcodes4", "postcodes6", "provincies". For add_map(), this is determined automatically if left blank.

data

data set to join left to the geodata

by

column to join by

crop_certe

logical to keep only the Certe region

sf_data

a data set of class 'sf'

...

filters to set

xmin, xmax, ymin, ymax

coordination filters for sf_data, given in degrees following EPSG:4326 ('WGS 84')

longitudes

vector of longitudes

latitudes

vector of latitudes

crs

the coordinate reference system (CRS) to use as output

Value

An sf model. The column with geodata is always called "geometry".

Details

All of these functions will check if the sf package is installed, and will load its namespace (but not attach the package).

crop_certe() cuts any geometry to the Certe region (more of less): the Northern three provinces of the Netherlands and municipalities of Noordoostpolder, Urk, and Steenwijkerland. This will be based on postcodes.

filter_geolocation() filters an sf object on qualitative values such as 'gemeente' and 'provincie'. The input data sf_data will be joined with postcodes and filtering can thus be done on any of these columns: postcode, inwoners, inwoners_man, inwoners_vrouw, plaats, gemeente, provincie, nuts3, ggdregio.

filter_sf() filters an sf object on coordinates, and is internally used by crop_certe().

convert_to_degrees_CRS4326() will transform SF data to WGS 84 – WGS84 - World Geodetic System 1984, used in GPS, CRS 4326.

convert_to_metre_CRS28992() will transform SF data to Amersfoort / RD New – Netherlands - Holland - Dutch, CRS 28992.

latitude() specifies the north-south position ('y axis') and longitude() specifies the east-west position ('x axis'). They return the numeric coordinate of the centre of a simple feature.

Examples

# Retrieving and joining maps ------------------------------------------

get_map() # defaults to the geo_postcodes4 data set
#> Simple feature collection with 4068 features and 3 fields (with 1 geometry empty)
#> Geometry type: MULTIPOLYGON
#> Dimension:     XY
#> Bounding box:  xmin: 13565.4 ymin: 306846.2 xmax: 278026.1 ymax: 615045.3
#> Projected CRS: Amersfoort / RD New
#> First 10 features:
#>    postcode inwoners oppervlakte_km2                       geometry
#> 1      1011     9630       0.9714760 MULTIPOLYGON (((122183.3 48...
#> 2      1012     8545       1.1559603 MULTIPOLYGON (((122049.3 48...
#> 3      1013    21255       4.8815624 MULTIPOLYGON (((120047.8 49...
#> 4      1014     2865       2.9208476 MULTIPOLYGON (((121228.2 48...
#> 5      1015    14855       0.7525791 MULTIPOLYGON (((120603.3 48...
#> 6      1016    10915       0.8013765 MULTIPOLYGON (((121164 4873...
#> 7      1017    12715       1.2981518 MULTIPOLYGON (((121004.7 48...
#> 8      1018    21195       2.1414293 MULTIPOLYGON (((123455.3 48...
#> 9      1019    18820       3.8735743 MULTIPOLYGON (((125689.6 48...
#> 10     1021     6895       1.2537301 MULTIPOLYGON (((123335 4890...

# adding a map applies a RIGHT JOIN to get all relevant geometric data
data.frame(postcode = 7753, number_of_cases = 3) |> 
  add_map()
#> Joining, by postcode
#> Simple feature collection with 1039 features and 4 fields
#> Geometry type: MULTIPOLYGON
#> Dimension:     XY
#> Bounding box:  xmin: 119098.8 ymin: 513471.6 xmax: 278026.1 ymax: 615045.3
#> Projected CRS: Amersfoort / RD New
#> First 10 features:
#>    postcode inwoners oppervlakte_km2 number_of_cases
#> 1      7705      345        2.659637              NA
#> 2      7741     9040       21.580447              NA
#> 3      7742     6445       17.375714              NA
#> 4      7751     3870       28.908806              NA
#> 5      7753      685        9.267895               3
#> 6      7754      375       10.559860              NA
#> 7      7755      365       11.056124              NA
#> 8      7756      245        6.768673              NA
#> 9      7761     4410       25.846640              NA
#> 10     7764      465        1.061360              NA
#>                          geometry
#> 1  MULTIPOLYGON (((231512.8 51...
#> 2  MULTIPOLYGON (((247054.9 52...
#> 3  MULTIPOLYGON (((254346.1 52...
#> 4  MULTIPOLYGON (((249130.2 52...
#> 5  MULTIPOLYGON (((241419.9 52...
#> 6  MULTIPOLYGON (((248946.4 52...
#> 7  MULTIPOLYGON (((250955.8 52...
#> 8  MULTIPOLYGON (((254049.2 52...
#> 9  MULTIPOLYGON (((256878.3 52...
#> 10 MULTIPOLYGON (((254998.5 52...


# Cropping to Certe region ---------------------------------------------

# Note: provinces do not include Flevoland
geo_provincies |> crop_certe()
#> Simple feature collection with 3 features and 3 fields
#> Geometry type: MULTIPOLYGON
#> Dimension:     XY
#> Bounding box:  xmin: 119098.8 ymin: 514322.3 xmax: 278026.1 ymax: 619352.4
#> Projected CRS: Amersfoort / RD New
#>   provincie inwoners oppervlakte_km2                       geometry
#> 1   Drenthe   494705        2680.368 MULTIPOLYGON (((228930.1 57...
#> 2 Friesland   651430        3531.269 MULTIPOLYGON (((154047.9 56...
#> 3 Groningen   586920        2392.983 MULTIPOLYGON (((276560.6 58...

# but other geometries do, such as geo_gemeenten
if (require("certeplot2")) {
  geo_gemeenten |> crop_certe() |>    # cropped municipalities
    plot2(title = "Certe Region") |>
    add_sf(
      geo_provincies |> crop_certe(), # cropped provinces
      colour_fill = NA,
      colour = "black",
      linewidth = 0.5)
}
#> Loading required package: certeplot2
#> Loading required package: plot2
#>  Using category = inwoners
#>  Using datalabels = gemeente
#> ! Omitting printing of 43 datalabels - use datalabels = TRUE to force printing



# Filtering geometries -------------------------------------------------

geo_gemeenten |>
  crop_certe() |>
  # notice that the `provincie` column is not even in `geo_gemeenten`
  filter_geolocation(provincie == "Flevoland")
#> Simple feature collection with 2 features and 3 fields
#> Geometry type: MULTIPOLYGON
#> Dimension:     XY
#> Bounding box:  xmin: 168820.1 ymin: 513751.1 xmax: 197258.4 ymax: 539695.8
#> Projected CRS: Amersfoort / RD New
#>          gemeente inwoners oppervlakte_km2                       geometry
#> 1 Noordoostpolder    47580       466.06285 MULTIPOLYGON (((188921.9 51...
#> 2             Urk    21230        13.47839 MULTIPOLYGON (((169681.2 52...
  
geo_gemeenten |>
  crop_certe() |>
  filter_geolocation(inwoners_vrouw >= 50000)
#> Simple feature collection with 3 features and 3 fields
#> Geometry type: MULTIPOLYGON
#> Dimension:     XY
#> Bounding box:  xmin: 171383.4 ymin: 517415 xmax: 269918.7 ymax: 592658.9
#> Projected CRS: Amersfoort / RD New
#>     gemeente inwoners oppervlakte_km2                       geometry
#> 1      Emmen   107025        346.1279 MULTIPOLYGON (((266296.6 54...
#> 2  Groningen   233265        197.8553 MULTIPOLYGON (((245194.7 59...
#> 3 Leeuwarden   124470        255.1755 MULTIPOLYGON (((178314.1 58...

if (require("certeplot2")) {
  geo_postcodes4 |> 
    filter_geolocation(gemeente == "Tytsjerksteradiel") |> 
    plot2(category = inwoners,
          datalabels = postcode)

}
#>  Assuming datalabels.centroid = TRUE. Set to FALSE for a point-on-surface
#> placing of datalabels.


# filter on a latitude of 52.5 degrees and higher
geo_provincies |> filter_sf(ymin = 52.5)
#> Simple feature collection with 2 features and 3 fields
#> Geometry type: MULTIPOLYGON
#> Dimension:     XY
#> Bounding box:  xmin: 119098.8 ymin: 514322.3 xmax: 269918.7 ymax: 615024.5
#> Projected CRS: Amersfoort / RD New
#>   provincie inwoners oppervlakte_km2                       geometry
#> 1   Drenthe   494705        2680.368 MULTIPOLYGON (((228930.1 57...
#> 2 Friesland   651430        3531.269 MULTIPOLYGON (((154047.9 56...


# Transforming Coordinate Reference System (CRS) -----------------------

geo_provincies |> convert_to_degrees_CRS4326()
#> Simple feature collection with 12 features and 3 fields
#> Geometry type: MULTIPOLYGON
#> Dimension:     XY
#> Bounding box:  xmin: 3.358378 ymin: 50.75037 xmax: 7.227498 ymax: 53.55523
#> Geodetic CRS:  WGS 84
#> First 10 features:
#>        provincie inwoners oppervlakte_km2                       geometry
#> 1        Drenthe   494705        2680.368 MULTIPOLYGON (((6.493505 53...
#> 2      Flevoland   428210        1466.570 MULTIPOLYGON (((5.533445 52...
#> 3      Friesland   651430        3531.269 MULTIPOLYGON (((5.373002 53...
#> 4     Gelderland  2096460        5118.931 MULTIPOLYGON (((5.605929 52...
#> 5      Groningen   586920        2392.983 MULTIPOLYGON (((7.208053 53...
#> 6        Limburg  1115835        2210.001 MULTIPOLYGON (((5.932767 51...
#> 7  Noord-Brabant  2573810        5054.037 MULTIPOLYGON (((4.595966 51...
#> 8  Noord-Holland  2887460        2864.383 MULTIPOLYGON (((5.326332 52...
#> 9     Overijssel  1166335        3408.845 MULTIPOLYGON (((5.7963 52.5...
#> 10       Utrecht  1360955        1553.980 MULTIPOLYGON (((5.021543 52...

geo_provincies |> convert_to_metre_CRS28992()
#> Simple feature collection with 12 features and 3 fields
#> Geometry type: MULTIPOLYGON
#> Dimension:     XY
#> Bounding box:  xmin: 13565.4 ymin: 306846.2 xmax: 278026.1 ymax: 619352.4
#> Projected CRS: Amersfoort / RD New
#> First 10 features:
#>        provincie inwoners oppervlakte_km2                       geometry
#> 1        Drenthe   494705        2680.368 MULTIPOLYGON (((228930.1 57...
#> 2      Flevoland   428210        1466.570 MULTIPOLYGON (((164912.9 51...
#> 3      Friesland   651430        3531.269 MULTIPOLYGON (((154047.9 56...
#> 4     Gelderland  2096460        5118.931 MULTIPOLYGON (((169898.4 48...
#> 5      Groningen   586920        2392.983 MULTIPOLYGON (((276560.6 58...
#> 6        Limburg  1115835        2210.001 MULTIPOLYGON (((192680.3 41...
#> 7  Noord-Brabant  2573810        5054.037 MULTIPOLYGON (((100303.1 41...
#> 8  Noord-Holland  2887460        2864.383 MULTIPOLYGON (((150846.9 47...
#> 9     Overijssel  1166335        3408.845 MULTIPOLYGON (((182721.3 51...
#> 10       Utrecht  1360955        1553.980 MULTIPOLYGON (((130059 4794...


# Other functions ------------------------------------------------------

degrees_to_sf(4.5, 54)
#> Simple feature collection with 1 feature and 0 fields
#> Geometry type: POINT
#> Dimension:     XY
#> Bounding box:  xmin: 96811.73 ymin: 668666 xmax: 96811.73 ymax: 668666
#> Projected CRS: Amersfoort / RD New
#>                  geometry
#> 1 POINT (96811.73 668666)

if (require("certeplot2")) {
  geo_provincies |>
      crop_certe() |> 
      plot2(category = NULL, colour_fill = NA) |> 
      add_sf(degrees_to_sf(6.5, 53),
             datalabels = "Some Point!")
}
#>  Assuming datalabels.centroid = TRUE. Set to FALSE for a point-on-surface
#> placing of datalabels.
#>  Using datalabels = provincie


latitude(geo_provincies)
#>  [1] 52.86228 52.52686 53.10848 52.06070 53.21673 51.20786 51.56101 52.58150
#>  [9] 52.44379 52.08348 51.45178 51.94915
longitude(geo_provincies)
#>  [1] 6.618508 5.595075 5.844877 5.939833 6.745329 5.933201 5.189413 4.870502
#>  [9] 6.445325 5.163127 3.834928 4.477864