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Set Geometry Column of an sf Object in a Pipeline

Source: R/spat_set_geometry.R
set_geometry.Rd

Sets the active geometry column of a simple feature (sf) object to a specified column, designed for use in data processing pipelines (e.g., with %>%). Ensures spatial operations use the correct geometry column.

Usage

set_geometry(sf_object = NULL, geometry_column = NULL)

Arguments

sf_object

An sf object with at least one geometry (sfc) column. Cannot be NULL or non-sf.

geometry_column

Character. Name of an existing sfc geometry column in sf_object to set as the active geometry. Must be a single, non-empty character string.

Value

The modified sf object with the active geometry column set to geometry_column.

Note

The geometry_column must be an existing sfc column in sf_object. Use with caution to avoid overwriting the active geometry unintentionally.

Author

Ahmed El-Gabbas

Examples

load_packages(sf, dplyr, ggplot2)

# example data with multiple geometry columns
nc <- sf::st_read(
  dsn = system.file("shape/nc.shp", package = "sf"), quiet = TRUE) %>%
  dplyr::select(AREA)
# add a new geometry column
nc$centroid <- sf::st_centroid(st_geometry(nc))

nc
#> Simple feature collection with 100 features and 1 field
#> Active geometry column: geometry
#> Geometry type: MULTIPOLYGON
#> Dimension:     XY
#> Bounding box:  xmin: -84.32385 ymin: 33.88199 xmax: -75.45698 ymax: 36.58965
#> Geodetic CRS:  NAD27
#> First 10 features:
#>     AREA                       geometry                   centroid
#> 1  0.114 MULTIPOLYGON (((-81.47276 3...  POINT (-81.49823 36.4314)
#> 2  0.061 MULTIPOLYGON (((-81.23989 3... POINT (-81.12513 36.49111)
#> 3  0.143 MULTIPOLYGON (((-80.45634 3... POINT (-80.68573 36.41252)
#> 4  0.070 MULTIPOLYGON (((-76.00897 3... POINT (-76.02719 36.40714)
#> 5  0.153 MULTIPOLYGON (((-77.21767 3... POINT (-77.41046 36.42236)
#> 6  0.097 MULTIPOLYGON (((-76.74506 3... POINT (-76.99472 36.36142)
#> 7  0.062 MULTIPOLYGON (((-76.00897 3... POINT (-76.23402 36.40122)
#> 8  0.091 MULTIPOLYGON (((-76.56251 3... POINT (-76.70446 36.44428)
#> 9  0.118 MULTIPOLYGON (((-78.30876 3... POINT (-78.11042 36.39693)
#> 10 0.124 MULTIPOLYGON (((-80.02567 3... POINT (-80.23429 36.40042)

# set centroid as active geometry in a pipeline
nc_modified <- set_geometry(nc, "centroid")
nc_modified
#> Simple feature collection with 100 features and 1 field
#> Active geometry column: centroid
#> Geometry type: POINT
#> Dimension:     XY
#> Bounding box:  xmin: -84.05986 ymin: 34.07671 xmax: -75.8095 ymax: 36.49111
#> Geodetic CRS:  NAD27
#> First 10 features:
#>     AREA                       geometry                   centroid
#> 1  0.114 MULTIPOLYGON (((-81.47276 3...  POINT (-81.49823 36.4314)
#> 2  0.061 MULTIPOLYGON (((-81.23989 3... POINT (-81.12513 36.49111)
#> 3  0.143 MULTIPOLYGON (((-80.45634 3... POINT (-80.68573 36.41252)
#> 4  0.070 MULTIPOLYGON (((-76.00897 3... POINT (-76.02719 36.40714)
#> 5  0.153 MULTIPOLYGON (((-77.21767 3... POINT (-77.41046 36.42236)
#> 6  0.097 MULTIPOLYGON (((-76.74506 3... POINT (-76.99472 36.36142)
#> 7  0.062 MULTIPOLYGON (((-76.00897 3... POINT (-76.23402 36.40122)
#> 8  0.091 MULTIPOLYGON (((-76.56251 3... POINT (-76.70446 36.44428)
#> 9  0.118 MULTIPOLYGON (((-78.30876 3... POINT (-78.11042 36.39693)
#> 10 0.124 MULTIPOLYGON (((-80.02567 3... POINT (-80.23429 36.40042)

attr(nc, "sf_column")
#> [1] "geometry"
attr(nc_modified, "sf_column")
#> [1] "centroid"

ggplot2::ggplot() +
  ggplot2::geom_sf(data = nc, aes(fill = NULL)) +
  ggplot2::geom_sf(data = nc_modified, colour = "red") +
  ggplot2::theme_minimal()