rdwd: climate data from the German Weather Service
2019-05-30
Vignette Rmd source code (Not on CRAN to reduce load on DWD server through daily new builds and checks of the vignette)
Interactive map vignette
use cases vignette
Links to the function help pages lead to 404 on CRAN, but work in locally opened vignettes.
Package structure
To use the observation datasets, rdwd has been designed to mainly do 3 things:
selectDWD: facilitate file selection, e.g. for certain station names (with findID), by geographical location (see map and nearbyStations), by temporal resolution (res = 1/10 minutes, hourly, daily, monthly, annual), variables (var = temperature, rain, wind, sun, clouds, etc) or observation period (per = historical long term records or the current year)
dataDWD: download a file (or multiple files, without getting banned by the FTP-server)
readDWD: read that data into R (including useful defaults for metadata)
selectDWD uses the result from indexFTP which recursively lists all the files on an FTP-server (using RCurl::getURL). As this is time consuming, the result is stored in the package dataset fileIndex. From this, metaIndex and geoIndex are derived.
TOC
Package installation
On Linux, instead of the last line above, use in the terminal (with lowercase rcurl):
sudo apt-get install r-cran-rcurl
If direct installation from CRAN doesn’t work, your R version might be too old. In that case you’ll need to update R.
TOC
Basic usage
## 'data.frame': 550 obs. of 19 variables:
## $ STATIONS_ID : int 3987 3987 3987 3987 3987 3987 3987 3987 3987 3987 ...
## $ MESS_DATUM : POSIXct, format: "2017-11-25" "2017-11-26" ...
## $ QN_3 : int 10 10 10 10 10 10 10 10 10 10 ...
## $ FX.Windspitze : num 9.9 11.5 14.7 12.3 8.2 6 5.5 5.2 10.9 13.9 ...
## $ FM.Windgeschwindigkeit : num 3.7 5.2 6 5.2 3.4 2.3 2.5 1.9 4.5 6 ...
## $ QN_4 : int 3 3 3 3 3 3 3 3 3 3 ...
## $ RSK.Niederschlagshoehe : num 16.1 0.2 3.6 0 0.2 0 0 0 0.8 2.1 ...
## $ RSKF.Niederschlagsform : int 6 6 6 6 6 6 6 0 8 8 ...
## $ SDK.Sonnenscheindauer : num 0 2.72 2.53 1.42 6.62 ...
## $ SHK_TAG.Schneehoehe : int 0 0 0 0 0 0 0 0 0 0 ...
## $ NM.Bedeckungsgrad : num 7.2 5.6 6.7 7.2 5.3 6 7.3 7.2 6 6 ...
## $ VPM.Dampfdruck : num 8 6.8 7 7.7 6.3 6.1 6.2 6.6 5.7 7 ...
## $ PM.Luftdruck : num 998 1005 1002 992 994 ...
## $ TMK.Lufttemperatur : num 3.8 2.7 3.5 5.4 2.1 0.9 1 1.7 -0.4 2.9 ...
## $ UPM.Relative_Feuchte : num 99.2 92.3 89.6 86 89 ...
## $ TXK.Lufttemperatur_Max : num 5.5 5 5.2 6.9 5.6 4.2 3.5 3.1 2.4 5.1 ...
## $ TNK.Lufttemperatur_Min : num 1.6 -0.1 0.9 3.8 -0.3 -1.3 -1.3 -1.8 -2.5 0.8 ...
## $ TGK.Lufttemperatur_5cm_min: num -0.3 -2.2 -1.4 2.6 -2.2 -3.5 -3.2 -3.7 -5.3 -1.7 ...
## $ eor : Factor w/ 1 level "eor": 1 1 1 1 1 1 1 1 1 1 ...
TOC
Plotting examples
Recent temperature time series:
par(mar=c(4,4,2,0.5), mgp=c(2.7, 0.8, 0), cex=0.8)
plot(clim[,c(2,14)], type="l", xaxt="n", las=1, main="Daily temp Potsdam")
berryFunctions::monthAxis() ; abline(h=0)
mtext("Source: Deutscher Wetterdienst", adj=-0.1, line=0.5, font=3)
Long term climate graph:
link <- selectDWD("Goettingen", res="monthly", var="kl", per="h")
clim <- dataDWD(link, quiet=TRUE)
clim$month <- substr(clim$MESS_DATUM_BEGINN,5,6)
temp <- tapply(clim$MO_TT, clim$month, mean, na.rm=TRUE)
prec <- tapply(clim$MO_RR, clim$month, mean, na.rm=TRUE)
berryFunctions::climateGraph(temp, prec, main="Goettingen")
mtext("Source: Deutscher Wetterdienst", adj=-0.05, line=2.8, font=3)
TOC
Station selection
Weather stations can be selected geographically with the interactive map. All stations within a certain radius around a given lat-long position can be obtained with nearbyStations.
The DWD station IDs can be obtained from station names with
## Potsdam
## 3987
## Warning: source -> withVisible -> eval -> eval -> createBerrysVignettes -
## > rmarkdown::render -> knitr::knit -> call_block -> block_exec -> in_dir -
## > evaluate -> evaluate::evaluate -> evaluate_call -> timing_fn -> handle -
## > findID: ID determined from name 'Koeln' has 4 elements (2665, 2666, 2667,
## 2968).
## Koeln-Bonn Koeln-Botanischer Garten Koeln-Porz-Eil
## 2667 2665 2666
## Koeln-Stammheim
## 2968
TOC
Available files
File selection by station name/id and folder happens with selectDWD. It needs an index of all the available files on the server. The package contains such an index (fileIndex) that is updated (at least) with each CRAN release of the package. The selectDWD documentation contains an overview of the FTP folder structure.
If you find the file index to be outdated (Error in download.file … : cannot open URL), please let me know and I will update it. Meanwhile, use current=TRUE in selectDWD:
fileIndex is created with the function indexFTP used in the last section of rdwd-package.R.
### This chunk is not evaluated ###
# recursively list files on the FTP-server:
files <- indexFTP("hourly/sun") # use dir="some_path" to save the output elsewhere
berryFunctions::headtail(files, 5, na=TRUE)
# indexFTP uses a folder to resume indexing after getting banned:
gridindex <- indexFTP("radolan","ftp://opendata.dwd.de/climate_environment/CDC/grids_germany/hourly")
gridindex <- indexFTP(gridindex,"ftp://opendata.dwd.de/climate_environment/CDC/grids_germany/hourly", sleep=1)
# with other FTP servers, this should also work...
funet <- indexFTP(base="ftp.funet.fi/pub/standards/w3/TR/xhtml11/", folder="")
p <- RCurl::getURL( "ftp.funet.fi/pub/standards/w3/TR/xhtml11/",
verbose=T, ftp.use.epsv=TRUE, dirlistonly=TRUE)
TOC
File selection
selectDWD is designed to be very flexible:
## [[1]]
## [1] "ftp://opendata.dwd.de/climate_environment/CDC/observations_germany/climate/hourly/sun/historical/ stundenwerte_SD_03987_18930101_20181231_hist.zip"
##
## [[2]]
## [1] "ftp://opendata.dwd.de/climate_environment/CDC/observations_germany/climate/hourly/sun/historical/ stundenwerte_SD_05705_19510101_20181231_hist.zip"
If res/var/per are left NA, an interactive selection is opened with the available options for the given station.
## [1] "ftp://opendata.dwd.de/climate_environment/CDC/observations_germany/climate/ daily/kl/recent/tageswerte_KL_03987_akt.zip"
## [2] "ftp://opendata.dwd.de/climate_environment/CDC/observations_germany/climate/ daily/kl/historical/tageswerte_KL_03987_18930101_20181231_hist.zip"
There may be a differing number of available files for several stations across all folders. That’s why the default outvec is FALSE (unless per="hr").
## [[1]]
## [1] "s_germany/climate/annual/more_precip/historical/jahreswerte_RR_03467_19930101_20181231_hist.zip"
## [2] "s_germany/climate/annual/more_precip/recent/jahreswerte_RR_03467_akt.zip"
## [3] "s_germany/climate/daily/more_precip/historical/tageswerte_RR_03467_19930601_20181231_hist.zip"
## [4] "s_germany/climate/daily/more_precip/recent/tageswerte_RR_03467_akt.zip"
## [5] "s_germany/climate/monthly/more_precip/historical/monatswerte_RR_03467_19930601_20171231_hist.zip"
## [6] "s_germany/climate/monthly/more_precip/historical/monatswerte_RR_03467_19930601_20181231_hist.zip"
## [7] "s_germany/climate/monthly/more_precip/recent/monatswerte_RR_03467_akt.zip"
##
## [[2]]
## [1] "s_germany/climate/annual/more_precip/historical/jahreswerte_RR_05116_19920101_20061231_hist.zip"
## [2] "s_germany/climate/daily/more_precip/historical/tageswerte_RR_05116_19920701_20061231_hist.zip"
## [3] "s_germany/climate/monthly/more_precip/historical/monatswerte_RR_05116_19920701_20061231_hist.zip"
TOC