sits (version 1.5.3)

sits_get_data.sf: Get time series using sf objects

Description

Retrieve a set of time series from a data cube and and put the result in a "sits tibble", which contains both the satellite image time series and their metadata. The samples parameter must be a sf object in POINT or POLYGON geometry. If start_date and end_date are not informed, the function uses these data from the cube.

Usage

# S3 method for sf
sits_get_data(
  cube,
  samples,
  ...,
  start_date = NULL,
  end_date = NULL,
  bands = NULL,
  impute_fn = impute_linear(),
  label = "NoClass",
  label_attr = NULL,
  n_sam_pol = 30L,
  pol_avg = FALSE,
  sampling_type = "random",
  multicores = 2L,
  progress = FALSE
)

Value

A tibble of class "sits" with set of time series <longitude, latitude, start_date, end_date, label>.

Arguments

cube

Data cube from where data is to be retrieved. (tibble of class "raster_cube").

samples

The name of a shapefile.

...

Specific parameters for specific cases.

start_date

Start of the interval for the time series - optional (Date in "YYYY-MM-DD" format).

end_date

End of the interval for the time series - optional (Date in "YYYY-MM-DD" format).

bands

Bands to be retrieved - optional (character vector).

impute_fn

Imputation function to remove NA.

label

Label to be assigned to all time series - optional

label_attr

Attribute in the sf object to be used as a polygon label.

n_sam_pol

Number of samples per polygon to be read for POLYGON or MULTIPOLYGON objects.

pol_avg

Logical: summarize samples for each polygon?

sampling_type

Spatial sampling type: random, hexagonal, regular, or Fibonacci.

multicores

Number of threads to process the time series (integer, with min = 1 and max = 2048).

progress

Logical: show progress bar?

Examples

if (sits_run_examples()) {
    # reading a shapefile from BDC (Brazil Data Cube)
    bdc_cube <- sits_cube(
        source = "BDC",
        collection = "CBERS-WFI-16D",
        bands = c("NDVI", "EVI"),
        tiles = c("007004", "007005"),
        start_date = "2018-09-01",
        end_date = "2018-10-28"
    )
    # define a shapefile to be read from the cube
    shp_file <- system.file("extdata/shapefiles/bdc-test/samples.shp",
        package = "sits"
    )
    # read a shapefile into an sf object
    sf_object <- sf::st_read(shp_file)
    # get samples from the BDC using an sf object
    time_series_bdc <- sits_get_data(
        cube = bdc_cube,
        samples = sf_object
    )
}