ee_as_sf: Convert an EE table in a sf object

Description

Convert an EE table in a sf object

Usage

ee_as_sf(
  x,
  dsn,
  overwrite = TRUE,
  crs = NULL,
  via = "getInfo",
  maxFeatures = 5000,
  container = "rgee_backup",
  selectors = NULL,
  quiet = FALSE
)

Arguments

EE table (ee$FeatureCollection) to be converted into a sf object.

dsn

Character. Output filename; in case dsn is missing ee_as_sf will create a temporary file.

overwrite

Logical. Delete data source dsn before attempting to write?.

crs

Integer or character. coordinate reference system for the EE table. If is NULL, ee_as_sf will take the CRS of the first element.

via

Character. Method to fetch data about the object. Multiple options supported. See details.

maxFeatures

Numeric. The maximum allowed number of features to export (ignore if via is not set as "getInfo"). The task will fail if the exported region covers more features. Defaults to 5000.

container

Character. Name of the folder ('drive') or bucket ('gcs') to be exported into (ignore if via is not defined as "drive" or "gcs").

selectors

The list of properties to include in the output, as a list of strings or a comma-separated string. By default, all properties are included.

quiet

logical. Suppress info message

Value

An sf object.

Details

ee_as_sf supports the download of ee$FeatureCollection, ee$Feature and ee$Geometry by three different options: "getInfo", "drive", and "gcs". When "getInfo" is set in the via argument, ee_as_sf will make an REST call to retrieve all the known information about the object. The advantage of use "getInfo" is a direct and faster download. However, there is a limitation of 5000 features by request which makes it not recommendable for large collections. Instead of "getInfo", the options: "drive" and "gcs" are suitable for large collections since they use an intermediate container, which may be Google Drive and Google Cloud Storage respectively. For getting more information about exporting data take a look at the Google Earth Engine Guide - Export data.

Examples

Run this code

# NOT RUN {
library(rgee)

ee_reattach() # reattach ee as a reserved word
ee_Initialize(drive = TRUE, gcs = TRUE)

# Region of interest
roi <- ee$Geometry$Polygon(list(
  c(-122.275, 37.891),
  c(-122.275, 37.868),
  c(-122.240, 37.868),
  c(-122.240, 37.891)
))

# TIGER: US Census Blocks Dataset
blocks <- ee$FeatureCollection("TIGER/2010/Blocks")
subset <- blocks$filterBounds(roi)
sf_subset <- ee_as_sf(x = subset)
plot(sf_subset)

# Create Random points in Earth Engine
region <- ee$Geometry$Rectangle(-119.224, 34.669, -99.536, 50.064)
ee_help(ee$FeatureCollection$randomPoints)
ee_randomPoints <- ee$FeatureCollection$randomPoints(region, 100)

# Download via GetInfo
sf_randomPoints <- ee_as_sf(ee_randomPoints)
plot(sf_randomPoints)

# Download via drive
sf_randomPoints_drive <- ee_as_sf(
  x = ee_randomPoints,
  via = 'drive'
)

# Download via GCS
sf_randomPoints_gcs <- ee_as_sf(
  x = subset,
  via = 'gcs',
  container = 'rgee_dev' #GCS bucket name
)
# }