Create an R object representing an SDP dataset.
Source:R/sdp_extraction_functions.R
sdp_get_raster.Rd
Create an R object representing an SDP dataset.
Usage
sdp_get_raster(
catalog_id = NULL,
url = NULL,
years = NULL,
months = NULL,
date_start = NULL,
date_end = NULL,
verbose = TRUE,
download_files = FALSE,
download_path = NULL,
overwrite = FALSE,
...
)
Arguments
- catalog_id
character. A single valid catalog number for an SDP dataset. This is in the
CatalogID
field for information returned bysdp_get_catalog()
.- url
character. A valid URL (e.g. https://path.to.dataset.tif) for the cloud-based dataset. You should specify either
catalog_id
orurl
, but not both.- years
numeric. For annual time-series data, a numeric vector specifying which years to return. The default
NULL
returns all available years.- months
numeric. For monthly time-series data, a numeric vector specifying which months of data to return. The default
NULL
returns all available months.- date_start
class
Date
. For daily time-series data, the first day of data to return.- date_end
class
Date
. For daily time-series data, the last day of data to return.- verbose
logical. Should the function print status and progress messages?
- download_files
logical. Should the function download files to disk? The default
FALSE
creates cloud-based representations of the data without downloading.- download_path
character. Destination path for downloaded files. This can be a relative or absolute path.
- overwrite
logical. Should files with the same names as the datasets be overwritten in
download_path
? IfFALSE
, the function will skip downloading files that already exist in the destination.- ...
Other arguments to pass to the
terra::rast()
function.
Value
An R object (class terra::SpatRaster
) representing the raster dataset.
Details
Files headers are read from cloud-based datasets using the terra
package, but the full dataset is not downloaded locally unless download_files=TRUE
. Instead terra
uses the web-based file system embedded in GDAL (VSICURL) to access datasets on the cloud. For large datasets and slow network connections, the function might take up to a minute to complete.
Specifying local downloads download_files=TRUE
might be more efficient for multi-layer data, but can take up lots of disk space.
Examples
## Lookup catalog number for a dataset.
cat <- sdp_get_catalog(domain='UG',type='Vegetation')
lc_id <- cat$CatalogID[cat$Product=='Basic Landcover']
## Connect to the dataset without downloading
landcover <- sdp_get_raster(lc_id)
landcover
#> class : SpatRaster
#> dimensions : 72603, 83004, 1 (nrow, ncol, nlyr)
#> resolution : 1, 1 (x, y)
#> extent : 305082, 388086, 4256064, 4328667 (xmin, xmax, ymin, ymax)
#> coord. ref. : WGS 84 / UTM zone 13N (EPSG:32613)
#> source : UG_landcover_1m_v4.tif
#> color table : 1
#> name : UG_landcover_1m_v4