Translate Request

Locating a dataset

You could use the R functions cms_product_details() and cms_product_metadata() to look for Copernicus Marine Service data. If you prefer using a graphical user interface, you can use the website to find a suitable dataset: https://data.marine.copernicus.eu/products.

Once you have located a suitable dataset on the website, the ‘form’ link can be used to enter a subset of the data. The screen capture video below demonstrates how this form can be used to specify a request. It also shows how you can copy this request in the form of command line (or Python) code to the clipboard.

Demonstration of copying request code to clipboard

Once on the clipboard, you can translate the request code to an R named list with cms_translate().

Download data with request

The example below demonstrates how the strategy above can be used to download a subset of data. It shows how you can translate the command line code obtained from the website can be translated into a named list.

library(CopernicusMarine)
## Example of command line code
## copied from website:
cli_code <-
"copernicusmarine subset
  --dataset-id cmems_mod_glo_phy_anfc_0.083deg_PT1H-m
  --variable uo
  --variable vo
  --start-datetime 2025-01-01T00:00:00
  --end-datetime 2025-01-01T23:00:00
  --minimum-longitude -2
  --maximum-longitude 8
  --minimum-latitude 52
  --maximum-latitude 59
  --minimum-depth 0.49402499198913574
  --maximum-depth 0.49402499198913574"

translated <- cms_translate(cli_code)
summary(translated)
#>               Length Class   Mode     
#> product       1      -none-  character
#> layer         1      -none-  character
#> variable      2      -none-  character
#> region        4      -none-  numeric  
#> timerange     2      POSIXct numeric  
#> verticalrange 2      -none-  numeric

Note that in the example above, the code is explicitly entered in the code and passed as an argument to the cms_translate()-call. In most cases it is not necessary. When you leave the text argument of cms_translate() empty, it will look for a request on the system clipboard.

Now that you have translated the code, how can you actually download the data? You can pass the named last as arguments to cms_download_subset() using do.call(). Like this:

result <- do.call(cms_download_subset, translated)
plot(result, col = hcl.colors(100), axes = TRUE)

Data downloaded using translated query code