Extracting data.frame from simple features object in R

Question

Is there an sf-native (i.e. "correct") way of extracting everything except the geometry column from a simple features object? This works

df <- dplyr::select(as.data.frame(sf), -geometry)

but the select( , -geometry) step feels unnecessary. Also, it doesn't remove the geometry attributes.

Answer 1

To drop the geometry column, use st_drop_geometry():

library(sf)
nc <-  st_read(system.file("shape/nc.shp", package="sf"), quiet = TRUE)
nc_df2 <- nc %>% st_drop_geometry()
class(nc_df2)
#> [1] "data.frame"

Before st_drop_geometry() was added to the sf package (in November, 2018), one could produce the same result using the st_set_geometry() function, like this:

library(sf)
nc <-  st_read(system.file("shape/nc.shp", package="sf"), quiet = TRUE)
class(nc)
#> [1] "sf"         "data.frame"

nc_df <- nc %>% st_set_geometry(NULL)
class(nc_df)
#> [1] "data.frame"

Answer 2

Set the st_geometry property to NULL.

library(sf)
nc <-  st_read(system.file("shape/nc.shp", package="sf"), quiet = TRUE)
class(nc)
## [1] "sf"         "data.frame"
st_geometry(nc) <- NULL
class(nc)
## [1] "data.frame"

Also (though this won't remove the attr(nc, "sf_column"):

nc <-  st_read(system.file("shape/nc.shp", package="sf"), quiet = TRUE)
as.data.frame(nc)

Answer 3

why not simply select the columns that you would like?

as.data.frame(sf[,"some column name"])[,1]

Answer 4

as.data.frame(your_sf_object)[,-ncol(your_sf_object)] returns all the attribute columns except for its geometry. Also, use as.data.frame(your_sf_object)[,-8] if your 8th column is geometry.

If you prefer to use data.table rather than data.frame, you can use

data.table(your_sf_object)[,-ncol(your_sf_object),with=F]

or data.table(your_sf_object)[,-8,with=F] if your 8th column is geometry.

NOTE: This is my answer to an already old question, but time will come when I need this solution again but I forgot how I did it, so this is a good place to store the solution. Anyway, I got this solution from this thread. Sincerely, Yours Truly...