# geotargets [](https://www.repostatus.org/#active) [](https://wlandau.github.io/targetopia/) [](https://github.com/ropensci/geotargets/actions/workflows/R-CMD-check.yaml) [](https://app.codecov.io/gh/ropensci/geotargets?branch=master) [](https://github.com/ropensci/geotargets/actions?query=workflow%3Apkgcheck) [](https://github.com/ropensci/software-review/issues/675) [](https://community.r-multiverse.org/geotargets) [](https://CRAN.R-project.org/package=geotargets) `geotargets` extends [`targets`](https://github.com/ropensci/targets) to work with geospatial data formats, such as rasters and vectors (e.g., shapefiles). Currently we support raster and vector formats for the [`terra`](https://github.com/rspatial/terra) package. If you are unfamiliar with targets, we recommend watching [“targets in 4 minutes”](https://docs.ropensci.org/targets/#get-started-in-4-minutes). ## How to cite geotargets One example citation of geotargets could be as follows: “R packages used in this analysis included (list R packages used), targets, and geotargets (Tierney, N., Scott, E., & Brown, A, 2024). Here is the full bibliographic reference for your references: > Tierney N, Scott E, Brown A (2024). “geotargets: ‘Targets’ Extensions > for Geospatial Formats.” . ## Installation You can install the development version of geotargets like so: ``` r install.packages("geotargets", repos = c("https://ropensci.r-universe.dev", "https://cran.r-project.org")) ``` ## Why `geotargets` If you want to use geospatial data formats (such as `terra`) with the [`targets`](https://github.com/ropensci/targets) package to build analytic reproducible pipelines, it involves writing a lot of custom targets wrappers. We wrote `geotargets` so you can use geospatial data formats with `targets`. To provide more detail on this, a common problem when using popular libraries like `terra` with `targets` is running into errors with read and write. Due to the limitations that come with the underlying C++ implementation in the `terra` library, there are specific ways to write and read these objects. See `?terra` for details. `geotargets` helps handle these write and read steps, so you don’t have to worry about them and can use targets as you are used to. In essence, if you’ve ever come across the error: Error in .External(list(name = "CppMethod__invoke_notvoid", address = , : NULL value passed as symbol address or Error: external pointer is not valid When trying to read in a geospatial raster or vector in targets, then `geotargets` for you :) # Examples We currently provide support for the `terra` package with `targets`. Below we show three examples of target factories: - `tar_terra_rast()` - `tar_terra_vect()` - `tar_terra_sprc()` - `tar_terra_sds()` - `tar_terra_tiles()` - `tar_stars()` You would use these in place of `tar_target()` in your targets pipeline, e.g., when you are doing work with `terra` raster, vector, or raster collection data. If you would like to see and download working examples for yourself, see the repos: - [demo-geotargets](https://github.com/njtierney/demo-geotargets) - [icebreaker](https://github.com/njtierney/icebreaker) ## `tar_terra_rast()`: targets with terra rasters ``` r library(targets) tar_dir({ # tar_dir() runs code from a temporary directory. tar_script({ library(geotargets) get_elev <- function() { terra::rast(system.file("ex", "elev.tif", package = "terra")) } list( tar_terra_rast( terra_rast_example, get_elev() ) ) }) tar_make() x <- tar_read(terra_rast_example) x }) #> + terra_rast_example dispatched #> ✔ terra_rast_example completed [65ms, 8.52 kB] #> ✔ ended pipeline [383ms, 1 completed, 0 skipped] #> class : SpatRaster #> size : 90, 95, 1 (nrow, ncol, nlyr) #> resolution : 0.008333333, 0.008333333 (x, y) #> extent : 5.741667, 6.533333, 49.44167, 50.19167 (xmin, xmax, ymin, ymax) #> coord. ref. : lon/lat WGS 84 (EPSG:4326) #> source : terra_rast_example #> name : elevation #> min value : 141 #> max value : 547 ``` ## `tar_terra_vect()`: targets with terra vectors ``` r tar_dir({ # tar_dir() runs code from a temporary directory. tar_script({ library(geotargets) lux_area <- function(projection = "EPSG:4326") { terra::project( terra::vect(system.file("ex", "lux.shp", package = "terra")), projection ) } list( tar_terra_vect( terra_vect_example, lux_area() ) ) }) tar_make() x <- tar_read(terra_vect_example) x }) #> + terra_vect_example dispatched #> ✔ terra_vect_example completed [72ms, 172.03 kB] #> ✔ ended pipeline [264ms, 1 completed, 0 skipped] #> class : SpatVector #> geometry : polygons #> dimensions : 12, 6 (geometries, attributes) #> extent : 5.74414, 6.528252, 49.44781, 50.18162 (xmin, xmax, ymin, ymax) #> source : terra_vect_example #> coord. ref. : lon/lat WGS 84 (EPSG:4326) #> names : ID_1 NAME_1 ID_2 NAME_2 AREA POP #> type : #> values : 1 Diekirch 1 Clervaux 312 1.808e+04 #> 1 Diekirch 2 Diekirch 218 3.254e+04 #> 1 Diekirch 3 Redange 259 1.866e+04 ``` ## `tar_terra_sprc()`: targets with terra raster collections ``` r tar_dir({ # tar_dir() runs code from a temporary directory. tar_script({ library(geotargets) elev_scale <- function(z = 1, projection = "EPSG:4326") { terra::project( terra::rast(system.file("ex", "elev.tif", package = "terra")) * z, projection ) } list( tar_terra_sprc( raster_elevs, # two rasters, one unaltered, one scaled by factor of 2 and # reprojected to interrupted goode homolosine command = terra::sprc(list( elev_scale(1), elev_scale(2, "+proj=igh") )) ) ) }) tar_make() x <- tar_read(raster_elevs) x }) #> + raster_elevs dispatched #> ✔ raster_elevs completed [191ms, 37.90 kB] #> ✔ ended pipeline [470ms, 1 completed, 0 skipped] #> class : SpatRasterCollection #> length : 2 #> nrow : 90, 115 #> ncol : 95, 114 #> nlyr : 1, 1 #> extent : 5.741667, 1558890, 49.44167, 5556741 (xmin, xmax, ymin, ymax) #> crs (first) : lon/lat WGS 84 (EPSG:4326) #> names : raster_elevs, raster_elevs ``` ## `tar_stars()`: targets with stars objects ``` r tar_dir({ # tar_dir() runs code from a temporary directory. tar_script({ library(geotargets) list( tar_stars( test_stars, stars::read_stars(system.file( "tif", "olinda_dem_utm25s.tif", package = "stars" )) ) ) }) tar_make() x <- tar_read(test_stars) x }) #> + test_stars dispatched #> ✔ test_stars completed [63ms, 49.90 kB] #> ✔ ended pipeline [275ms, 1 completed, 0 skipped] #> stars object with 2 dimensions and 1 attribute #> attribute(s): #> Min. 1st Qu. Median Mean 3rd Qu. Max. #> test_stars -1 6 12 21.66521 35 88 #> dimension(s): #> from to offset delta refsys point x/y #> x 1 111 288776 89.99 UTM Zone 25, Southern Hem... FALSE [x] #> y 1 111 9120761 -89.99 UTM Zone 25, Southern Hem... FALSE [y] ``` ## Code of Conduct Please note that the geotargets project is released with a [Contributor Code of Conduct](https://ropensci.org/code-of-conduct/). By contributing to this project, you agree to abide by its terms. ## Acknowledgements Logo design by Hubert Hałun at Appsilon.