[help] Is targets compatible with raster files?

[Cidree]

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Description

Hello. I was trying to create a pipeline where some of the steps create a raster file with the terra package. Here I provide my reprex:

_targets.R

# Load packages required to define the pipeline:
library(targets)

# Set target options:
tar_option_set(
    packages = c("dplyr", "geodata", "giscoR", "ggplot2", "terra")
)

# Run the R scripts in the R/ folder with your custom functions:
tar_source("R/workflow.R")
# tar_source("other_functions.R") # Source other scripts as needed.

# Replace the target list below with your own:
list(
    ## 1. Get data ------------------
    tar_target(
        read_country,
        get_country(country = "Spain")
    ),
    tar_target(
        read_soil,
        get_soil(var = "nitrogen", depth = 5)
    )
    # 2. Process data --------------
    tar_target(
      process_soil,
      crop_soil(read_soil, read_country)
    )
)

R/workflow.R

get_country <- function(country = "Spain") {
    ## Get data for a country
    country_sf <- gisco_get_nuts(
        country    = country,
        year       = 2021,
        nuts_level = 1
    )
    ## Remove Canary Islands if its Spain
    if (country == "Spain") {
        country_sf <- country_sf |>
            filter(NAME_LATN != "Canarias")
    }
    ## Return
    return(country_sf)
}

get_soil <- function(var = "nitrogen", depth = 5) {
    soil_world(var = var, depth = depth, path = tempdir())
}

crop_soil <- function(soil, country) {
    soil %>%
        crop(country) %>%
        mask(country)
}

When I run tar_make() it fails when it gets to the final step process_soil with the error:

v skipped target read_country
v skipped target read_soil
> dispatched target process_soil
x errored target process_soil
x errored pipeline [3.89 seconds]
Error:
! Error running targets::tar_make()
Error messages: targets::tar_meta(fields = error, complete_only = TRUE)
Debugging guide: https://books.ropensci.org/targets/debugging.html
How to ask for help: https://books.ropensci.org/targets/help.html
Last error message:
    error in evaluating the argument 'x' in selecting a method for function 'mask': external pointer is not valid
Last error traceback:
    crop_soil(read_soil, read_country)
    soil %>% crop(country) %>% mask(country)
    mask(., country)
    crop(., country)
    crop(., country)
    .local(x, y, ...)
    x@cpp$crop(y@cpp, snap[1], extend[1], opt)
    stop(list("external pointer is not valid", NULL, NULL))
    (function (cond)  .Internal(C_tryCatchHelper(addr, 1L, cond)))(list("ext...
    .handleSimpleError(function (condition)  {     state$error <- build_mess...
    h(simpleError(msg, call))

The problem arises because SpatRaster files cannot be exported as rds or other format that I see available in tar_target.
I found this post from the terra package where they give a workaround but they do not recommend the use of this functions but rather use writeRaster.

Is there any existing alternative for raster data?

[Cidree]

I just discovered ´targetopia´ and with it ´geotargets´, so I close this discussion