g_25000_c_polygons_only <- g_25000_c[st_is(x = g_25000_c, type =
"POLYGON"),] # with a comma
El 10/02/2023 a las 21:33, Manuel Sp?nola escribi?:
Thnak you very much Bede-Fazekas.
I got the following error:
g_25000_c_polygons_only <- g_25000_c[st_is(x = g_25000_c, type =
Error in `[.data.frame`(x, i) : undefined columns selected
El vie, 10 feb 2023 a las 11:53, Bede-Fazekas ?kos (<
bfalevlist at gmail.com>)
Dear Manuel,
technically, the result of st_intersection(x, y), where both x and y are
POLYGONs, can be POINT, LINESTRING, POLGYON and GEOMETRY as well. The
result is GEOMETRY if the type of the different features is not the same
(e.g. POLYGON+POINT).
You can subset the result in this way:
g_25000_c_polygons_only <- g_25000_c[st_is(x = g_25000_c, type =
"POLYGON")]
HTH,
?kos
___________
?kos Bede-Fazekas
Centre for Ecological Research, Hungary
2023.02.10. 18:32 keltez?ssel, Manuel Sp?nola ?rta:
Dear list members,
I am trying to "crop" a polygon (grid) with a polygon, but the result
sf object Geometry type: GEOMETRY, instead of an sf object Geometry
POLYGON.
How can I obtain an sf POLYGON?
nc = st_read(system.file("shape/nc.shp", package="sf"))
nc <- st_transform(nc, 3857)
g_50000 <- st_make_grid(nc, cellsize = 50000) |> st_as_sf()
g_50000 <- g_50000[nc, ]
g_50000_d <- st_union(g_50000)
g_25000 = st_make_grid(g_50000_d, cellsize = 25000) |> st_as_sf()
g_25000 # Geometry type: POLYGON
g_25000_c <- st_intersection(g_25000, g_50000_d)
g_25000_c # Geometry type: GEOMETRY