apply_pixel: Apply a function over (multi-band) pixels

In gdalcubes: Earth Observation Data Cubes from Satellite Image Collections

Apply a function over (multi-band) pixels

Description

This generic function applies a function on pixels of a data cube, an R array, or other classes if implemented.

Usage

apply_pixel(x, ...)

Arguments

x	input data
...	additional arguments passed to method implementations

Value

return value and type depend on the class of x

See Also

apply_pixel.cube

apply_pixel.array

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) 
}

v = cube_view(extent=list(left=388941.2, right=766552.4, 
              bottom=4345299, top=4744931, t0="2018-04", t1="2018-06"),
              srs="EPSG:32618", nx = 497, ny=526, dt="P1M")
              
L8.col = image_collection(file.path(tempdir(), "L8.db"))
apply_pixel(raster_cube(L8.col, v), "(B05-B04)/(B05+B04)", "NDVI") 



d <- c(4,16,128,128)
x <- array(rnorm(prod(d)), d)
y <- apply_pixel(x, function(v) {
  v[1] + v[2] + v[3] - v[4]
})

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