Stacking an existing RasterStack multiple times
r, raster, replication
Solution
You might like `mget` here, since it takes a `character` vector of object names and returns the object, so you can do this:
big.stack <- stack( mget( rep( "s" , 12 ) ) )
nlayers( big.stack )
#[1] 144
Or using `replicate()` to put them in a `list` if you don't like using `mget()`, and then stacking the `list` as a `list` of `rasterLayers` is valid input to `stack()`...
ll <- replicate( 12 , s )
big.stack2 <- stack( ll )
identical( big.stack , big.stack2 )
#[1] TRUE
Problem
My question is pretty similar to an unfortunately unanswered issue recently posted on Stackoverflow. I am dealing with a `RasterStack` object consisting of twelve layers (one for each month of the year), and I would like to replicate the layers ten times, ending up with a `RasterStack` consisting of 120 layers, with every 12th layer being similar (i.e., layer 1 is the same like layer 13 is the same like layer 25 and so on). For replication purposes, let's take an example from the `raster` package: ``` library(raster) file <- system.file("external/test.grd", package = "raster") s <- stack(file, file, file, file, file, file, file, file, file, file, file, file) stack(s, s, s, s, s, s, s, s, s, s) class : RasterStack dimensions : 115, 80, 9200, 120 (nrow, ncol, ncell, nlayers) resolution : 40, 40 (x, y) extent : 178400, 181600, 329400, 334000 (xmin, xmax, ymin, ymax) coord. ref. : +init=epsg:28992 +towgs84=565.237,50.0087,465.658,-0.406857,0.350733,-1.87035,4.0812 +proj=sterea +lat_0=52.15616055555555 +lon_0=5.38763888888889 +k=0.9999079 +x_0=155000 +y_0=463000 +ellps=bessel +units=m +no_defs names : test.1.1, test.2.1, test.3.1, test.4.1, test.5.1, test.6.1, test.7.1, test.8.1, test.9.1, test.10.1, test.11.1, test.12.1, test.1.2, test.2.2, test.3.2, ... min values : 128.434, 128.434, 128.434, 128.434, 128.434, 128.434, 128.434, 128.434, 128.434, 128.434, 128.434, 128.434, 128.434, 128.434, 128.434, ... max values : 1805.78, 1805.78, 1805.78, 1805.78, 1805.78, 1805.78, 1805.78, 1805.78, 1805.78, 1805.78, 1805.78, 1805.78, 1805.78, 1805.78, 1805.78, ... ``` Of course, it could be done manually like in the last line of code, but that seems quite inconvenient to me. Any suggestions on how to achieve my goal in a better way would be highly appreciated!