Is the "Modify the LAScatalog drivers" page still valid with locate_trees

[djes]

Hello,

As I'm having problems exporting to shapefiles due to the bitmerge value overflow, I'm trying to export locate_trees output to a single file (sqlite or gpkg) but I encounter a difficulty. The "Modify the LAScatalog drivers" page talks about SpatialPointsDataFrame and uses find_trees, but the locate_trees documentation says that the output is sf.

So I've rewritten the functions :

# Create a function that writes a sf into
# a SQLite database.
dbWrite_sf = function(x, path, name)
{
  x <- as.data.frame(x)
  con <- RSQLite::dbConnect(RSQLite::SQLite(), path)
  RSQLite::dbWriteTable(con, name, x, append = TRUE)
  RSQLite::dbDisconnect(con)
}

# Change the driver used to write sf objects
# User-defined drivers have the precedence

ctg_filter@output_options$drivers$sf = list(
   write = dbWrite_sf,
   extension = ".sqlite",
   object = "x",
   path = "path",
   param = list(name = "trees"))

opt_output_files(ctg_filter) <- paste0("tops/", "trees")

But I'm not sure about the x <- as.data.frame(x)

Is it the correct way to handle this ? Thank you...

[Jean-Romain]

The wiki page is outdated but the general idea did not change. For sf st_write already provide the internals to write in databases. I don't think you need to use bare bones RSQLite functions.

as.data.frame on Spatial*DataFrame returns the coordinates + the attributes. This is not the case for sf where it returns a data.frame with a sfc column that won't be writable.

[djes]

Ok, thank you, I'll check this !