[FEATURE] function to combine point and polygon representations of entities in a single command

[Robinlovelace]

Is your feature request related to a problem? Please describe.

Sometimes entities like pubs are represented as points and polygons but you have to manually get both then get the centroid of the polygons to get the result.

Describe the solution you'd like

A function, e.g. called oe_get_centroids() could solve the problem.

Describe alternatives you've considered

I've thought about adding this functionality in another package but think it would be a good fit here.

Additional context

Here's a prototype of such a function that seemed worked: https://github.com/cyipt/actdev/blob/main/code/get_pois.R

Happy to put in a PR this is a good idea!

[Robinlovelace]

Reprex:

# Get pubs in Leeds
source("https://github.com/cyipt/actdev/raw/main/code/get_pois.R")
q = "SELECT * FROM 'points' WHERE amenity IN ('pub')"
pubs_west_yorkshire = get_pois(region_name = "west yorkshire", q = q)
#> The input place was matched with: West Yorkshire
#> Warning: The query selected a layer which is different from layer argument. We
#> will replace the layer argument.
#> The chosen file was already detected in the download directory. Skip downloading.
#> The corresponding gpkg file was already detected. Skip vectortranslate operations.
#> Reading query `SELECT * FROM 'points' WHERE amenity IN ('pub')' from data source `/mnt/57982e2a-2874-4246-a6fe-115c199bc6bd/data/osm/geofabrik_west-yorkshire-latest.gpkg' 
#>   using driver `GPKG'
#> Simple feature collection with 925 features and 12 fields
#> Geometry type: POINT
#> Dimension:     XY
#> Bounding box:  xmin: -2.107578 ymin: 53.54942 xmax: -1.233516 ymax: 53.9456
#> Geodetic CRS:  WGS 84
#> The input place was matched with: West Yorkshire
#> Warning: The query selected a layer which is different from layer argument. We
#> will replace the layer argument.
#> The chosen file was already detected in the download directory. Skip downloading.
#> The corresponding gpkg file was already detected. Skip vectortranslate operations.
#> Reading query `SELECT * FROM 'multipolygons' WHERE amenity IN ('pub')' from data source `/mnt/57982e2a-2874-4246-a6fe-115c199bc6bd/data/osm/geofabrik_west-yorkshire-latest.gpkg' 
#>   using driver `GPKG'
#> Simple feature collection with 1 feature and 25 fields
#> Geometry type: MULTIPOLYGON
#> Dimension:     XY
#> Bounding box:  xmin: -1.533704 ymin: 53.84149 xmax: -1.533252 ymax: 53.84161
#> Geodetic CRS:  WGS 84
#> Loading required package: sf
#> Linking to GEOS 3.10.1, GDAL 3.4.0, PROJ 8.2.0; sf_use_s2() is TRUE
#> Warning in st_centroid.sf(osm_polygons): st_centroid assumes attributes are
#> constant over geometries of x
pubs_leeds = pubs_west_yorkshire[si::si_zones, ]
plot(pubs_leeds)

^{Created on 2022-04-25 by the reprex package (v2.0.1)}

[agila5]

Hi Robin and thanks for your message! I like the idea (maybe in a slightly more general form to mimic the key = ... and value = ... approach in osmdata), but I need some time to implement the first prototype. I will add a PR here as soon as possible.