rdwd

rdwd is an R package to select, download and read climate data from the German Weather Service (Deutscher Wetterdienst, DWD). They provide thousands of datasets with weather observations online at
ftp://opendata.dwd.de/climate_environment/CDC/observations_germany/climate
Since May 2019, rdwd also supports reading the Radolan (binary) raster data at
ftp://opendata.dwd.de/climate_environment/CDC/grids_germany

rdwd is available on CRAN:

It has been presented at FOSDEM 2017 and UseR!2017 in Brussels, featured in Rstudios data package list and written about in OSOR.

Usage of the package usually looks something like the following:

# download and install the rdwd package (only needed once):
install.packages("rdwd")
# if wanted, latest development version, incl. vignettes:
remotes::install_github("brry/rdwd", build_opts="--no-manual")

# load the package into library (needed in every R session):
library(rdwd)

# select a dataset (e.g. last year's daily climate data from Potsdam City):
link <- selectDWD("Potsdam", res="daily", var="kl", per="recent")

# Actually download that dataset, returning the local storage file name:
file <- dataDWD(link, read=FALSE)

# Read the file from the zip folder:
clim <- readDWD(file, varnames=TRUE)

# Inspect the data.frame:
str(clim)

You can also select datasets with the interactive map.
A general introduction to rdwd is available in the package vignette.
Long actual-usage examples can be found in the use cases vignette.

vignette("mapDWD") # interactive map, likely faster than CRAN link above
vignette("rdwd")   # package instructions and examples
vignette("cases")  # longer use case examples

help

I'm looking for someone to help implement multiple downloads in dataDWD via e.g. curl or wget. The requirements are as follows:

• works cross-platform
• is called from R
• has as few dependencies as possible
• does not fail completely at a single failure, e.g. can be called within try
• optimally enables a progress bar