Extract values from an ee$Image
at the
locations of a geometry object. Users can use ee$Geometry$*
,
ee$Feature
, ee$FeatureCollection
, sf or sfc object to filter
spatially. This function mimicking how extract currently works.
ee_extract( x, y, fun = ee$Reducer$mean(), scale = NULL, sf = FALSE, via = "getInfo", container = "rgee_backup", lazy = FALSE, quiet = FALSE, ... )
x  ee$Image. 

y  ee$Geometry$*, ee$Feature, ee$FeatureCollection, sfc or sf objects. 
fun  ee$Reducer object. Function to summarize the values. The function must take a single numeric value as an argument and return a single value. See details. 
scale  A nominal scale in meters of the Image projection to work in. By default 1000. 
sf  Logical. Should return an sf object? 
via  Character. Method to export the image. Three method are implemented: "getInfo", "drive", "gcs". 
container  Character. Name of the folder ('drive') or bucket ('gcs')
to be exported into (ignore if 
lazy  Logical. If TRUE, a 
quiet  Logical. Suppress info message. 
...  ee$Image$reduceRegions additional parameters. See

A data.frame or an sf object depending on the sf argument.
Column names are extracted from band names. Use ee$Image$rename
to
rename the bands of an ee$Image
. See ee_help(ee$Image$rename)
.
The reducer functions that return one value are:
allNonZero: Returns a Reducer that returns 1 if all of its
inputs are nonzero, 0 otherwise.
anyNonZero: Returns a Reducer that returns 1 if any of its
inputs are nonzero, 0 otherwise.
bitwiseAnd: Returns a Reducer that computes the bitwiseand summation of its inputs.
bitwiseOr: Returns a Reducer that computes the bitwiseor summation of its inputs.
count: Returns a Reducer that computes the number of nonnull inputs.
first: Returns a Reducer that returns the first of its inputs.
firstNonNull: Returns a Reducer that returns the first of its nonnull inputs.
kurtosis: Returns a Reducer that Computes the kurtosis of its inputs.
last: Returns a Reducer that returns the last of its inputs.
lastNonNull: Returns a Reducer that returns the last of its nonnull inputs.
max: Creates a reducer that outputs the maximum value of its (first) input. If numInputs is greater than one, also outputs the corresponding values of the additional inputs.
mean: Returns a Reducer that computes the (weighted) arithmetic mean of its inputs.
median: Create a reducer that will compute the median of the inputs. For small numbers of inputs (up to maxRaw) the median will be computed directly; for larger numbers of inputs the median will be derived from a histogram.
min: Creates a reducer that outputs the minimum value of its (first) input. If numInputs is greater than one, also outputs additional inputs.
mode: Create a reducer that will compute the mode of the inputs. For small numbers of inputs (up to maxRaw) the mode will be computed directly; for larger numbers of inputs the mode will be derived from a histogram.
product: Returns a Reducer that computes the product of its inputs.
sampleStdDev: Returns a Reducer that computes the sample standard deviation of its inputs.
sampleVariance: Returns a Reducer that computes the sample variance of its inputs.
stdDev: Returns a Reducer that computes the standard deviation of its inputs.
sum: Returns a Reducer that computes the (weighted) sum of its inputs.
variance: Returns a Reducer that computes the variance of its inputs.
if (FALSE) { library(rgee) library(sf) ee_Initialize(gcs = TRUE, drive = TRUE) # Define a Image or ImageCollection: Terraclimate terraclimate < ee$ImageCollection("IDAHO_EPSCOR/TERRACLIMATE") %>% ee$ImageCollection$filterDate("20010101", "20020101") %>% ee$ImageCollection$map( function(x) { date < ee$Date(x$get("system:time_start"))$format('YYYY_MM_dd') name < ee$String$cat("Terraclimate_pp_", date) x$select("pr")$rename(name) } ) # Define a geometry nc < st_read( dsn = system.file("shape/nc.shp", package = "sf"), stringsAsFactors = FALSE, quiet = TRUE ) #Extract values  getInfo ee_nc_rain < ee_extract( x = terraclimate, y = nc["NAME"], scale = 250, fun = ee$Reducer$mean(), sf = TRUE ) # Extract values  drive (lazy = TRUE) ee_nc_rain < ee_extract( x = terraclimate, y = nc["NAME"], scale = 250, fun = ee$Reducer$mean(), via = "drive", lazy = TRUE, sf = TRUE ) ee_nc_rain < ee_nc_rain %>% ee_utils_future_value() # Extract values  gcs (lazy = FALSE) ee_nc_rain < ee_extract( x = terraclimate, y = nc["NAME"], scale = 250, fun = ee$Reducer$mean(), via = "gcs", container = "rgee_dev", sf = TRUE ) # Spatial plot plot( ee_nc_rain["X200101_Terraclimate_pp_2001_01_01"], main = "2001 Jan Precipitation  Terraclimate", reset = FALSE ) }