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 examplesif (!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) # savefname =tempfile()as_json(cube, fname)# loadjson_cube(path = fname)
A data cube proxy object
Dimensions:
low high count pixel_size chunk_size
t 2018-01-01 2018-12-01 12 P1M 1
y 4345299 4744931 526 759.756653992395 384
x 388941.2 766552.4 497 759.781086519115 384
Bands:
name offset scale nodata unit
1 B01 0 1 NaN
2 B02 0 1 NaN
3 B03 0 1 NaN
4 B04 0 1 NaN
5 B05 0 1 NaN
6 B06 0 1 NaN
7 B07 0 1 NaN
8 B08 0 1 NaN
9 B09 0 1 NaN
10 B10 0 1 NaN
11 B11 0 1 NaN
12 BQA 0 1 NaN
Source Code
# json_cubeRead a data cube from a json description file```{r include=FALSE}library(gdalcubes)```## DescriptionRead a data cube from a json description file## Usage```rjson_cube(json, path =NULL)```## Arguments| Argument | Description ||:------------|:----------------------------------|| json | length-one character vector with a valid json data cube description || path | source data cube proxy object |## DetailsData cubes can be stored as JSON description files. These files do not store any data but the recipehow a data cube is constructed, i.e., the chain (or graph) of processes involved. Since data cube objects (as returned from [`raster_cube`](raster_cube.Rmd)) cannot be saved with normal R methods,the combination of [`as_json`](as_json.Rmd) and [`json_cube`](json_cube.Rmd) provides a cheap way to save virtual data cube objects across several R sessions, as in the examples.## Valuedata cube proxy object## Examples```{r}# create image collection from example Landsat data only # if not already done in other examplesif (!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) # savefname =tempfile()as_json(cube, fname)# loadjson_cube(path = fname) ```