json_cube: Read a data cube from a json description file

In gdalcubes: Earth Observation Data Cubes from Satellite Image Collections

Read a data cube from a json description file

Description

Read a data cube from a json description file

Usage

json_cube(json, path = NULL)

Arguments

json	length-one character vector with a valid json data cube description
path	source data cube proxy object

Details

Data cubes can be stored as JSON description files. These files do not store any data but the recipe how a data cube is constructed, i.e., the chain (or graph) of processes involved.

Since data cube objects (as returned from raster_cube) cannot be saved with normal R methods, the combination of as_json and json_cube provides a cheap way to save virtual data cube objects across several R sessions, as in the examples.

Value

data cube proxy object

Examples

# create image collection from example Landsat data only 
# if not already done in other examples
if (!file.exists(file.path(tempdir(), "L8.db"))) {
  L8_files <- list.files(system.file("L8NY18", package = "gdalcubes"),
                         ".TIF", recursive = TRUE, full.names = TRUE)
  create_image_collection(L8_files, "L8_L1TP", file.path(tempdir(), "L8.db"), quiet = TRUE) 
}

L8.col = image_collection(file.path(tempdir(), "L8.db"))
v = cube_view(extent=list(left=388941.2, right=766552.4, 
              bottom=4345299, top=4744931, t0="2018-01", t1="2018-12"),
              srs="EPSG:32618", nx = 497, ny=526, dt="P1M")
cube = raster_cube(L8.col, v) 

# save
fname = tempfile()
as_json(cube, fname)

# load
json_cube(path = fname)  

gdalcubes documentation built on May 29, 2024, 5:11 a.m.