Extract raster time series values at points in space and time

The package has one job: given a series of rasters that is described by a reader function rather than held in memory, and a set of points that each carry their own date-time, return the value of the series at each point.

Details

The series can be far larger than memory, and can live anywhere the reader can reach, because only the time slices actually needed are read, and each is read exactly once.

The reader contract

A reader is any function supporting two calls.

  read(returnfiles = TRUE, ...)        # -> data.frame with a `date` column
  read(date, inputfiles = files, ...)  # -> single-layer SpatRaster

The first call is the catalogue: one row per available time slice, in ascending date order. The second reads one slice. inputfiles is the catalogue handed back so the reader does not have to rebuild it.

Use xyt_reader_check() to test a function against the contract before handing it to extract_xyt().

See also

extract_xyt(), xyt_reader_check(), synthetic_reader()

Author

Maintainer: Michael D. Sumner mdsumner@gmail.com (ORCID) [copyright holder]

Authors:

• Michael D. Sumner mdsumner@gmail.com (ORCID) [copyright holder]