rdwd: climate data from the German Weather Service
2017-02-03
Vignette Rmd source code
Interactive map vignette
Package structure
To use those 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 mapDWD), by temporal resolution (hourly, daily, monthly), variables (temperature, rain, wind, sun, clouds, etc) or observation period (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 indexDWD 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, geoIndex, mapDWD and metaInfo are derived.
TOC
Package installation
install.packages("rdwd")
# get the latest development version from github:
berryFunctions::instGit("brry/rdwd")
# For full usage, as needed in indexDWD and metaDWD(..., current=TRUE):
install.packages("RCurl") # is only suggested, not mandatory dependency
If direct installation from CRAN doesn’t work, your R version might be too old. In that case, an update is really recommendable: r-project.org. If you can’t update R, try installing from source (github) via instGit as mentioned above. If that’s not possible either, you might be able to source some functions from the package zip folder
Vectorize(source)(dir("path/you/unzipped/to/rdwd-master/R", full=T))
TOC
Basic usage
tdir <- tempdir()
link <- selectDWD("Potsdam", res="daily", var="kl", per="recent")
file <- dataDWD(link, read=FALSE, dir=tdir, quiet=TRUE)
clim <- readDWD(file, dir=tdir)
str(clim)
## 'data.frame': 550 obs. of 18 variables:
## $ STATIONS_ID : int 3987 3987 3987 3987 3987 3987 3987 3987 3987 3987 ...
## $ MESS_DATUM : POSIXct, format: "2015-08-02" "2015-08-03" ...
## $ QUALITAETS_NIVEAU : int 3 3 3 3 3 3 3 3 3 3 ...
## $ LUFTTEMPERATUR : num 22.4 23.8 25.8 20.6 25.2 27.8 24.5 22.5 25.3 25.8 ...
## $ DAMPFDRUCK : num 11.7 13.3 15.7 15.4 15.8 17.4 18.6 15.3 17.7 19.1 ...
## $ BEDECKUNGSGRAD : num 4.5 2 2.9 4.9 3.6 3.4 4.4 2.3 3.3 4 ...
## $ LUFTDRUCK_STATIONSHOEHE : num 1007 1006 1002 1007 1004 ...
## $ REL_FEUCHTE : num 46.8 49.4 52.4 66.2 54.1 ...
## $ WINDGESCHWINDIGKEIT : num 3 3 5 3.4 3.4 4 4.3 3.5 3.8 3.8 ...
## $ LUFTTEMPERATUR_MAXIMUM : num 30 32.3 35.3 26.3 34.6 37.6 33.3 29.5 33.5 33.1 ...
## $ LUFTTEMPERATUR_MINIMUM : num 15.1 14 18.4 16.4 16.1 21.2 19.2 16.6 17.1 19.4 ...
## $ LUFTTEMP_AM_ERDB_MINIMUM: num 11.6 11.7 16.1 14.9 13.5 18.1 17.8 15.5 16.1 18.7 ...
## $ WINDSPITZE_MAXIMUM : num 8.1 9.2 17.3 9.1 9.6 9.1 12.5 8.2 8.4 11.7 ...
## $ NIEDERSCHLAGSHOEHE : num 0 0 4.1 0 0 0 0.1 0 0 0 ...
## $ NIEDERSCHLAGSHOEHE_IND : int 0 0 6 0 0 0 6 0 0 0 ...
## $ SONNENSCHEINDAUER : num 13.4 14.4 11.6 10.7 13.3 ...
## $ SCHNEEHOEHE : int 0 0 0 0 0 0 0 0 0 0 ...
## $ 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(2,4)], type="l", xaxt="n", las=1, main="Daily temp Potsdam")
berryFunctions::monthAxis(ym=TRUE) ; abline(h=0)
mtext("Source: Deutscher Wetterdienst", adj=-0.1, line=0.5, font=3)
Long term climate graph:
link <- selectDWD("Potsdam", res="monthly", var="kl", per="h")
clim <- dataDWD(link, quiet=TRUE)
clim$month <- substr(clim$MESS_DATUM_BEGINN,5,6)
temp <- tapply(clim$LUFTTEMPERATUR, clim$month, mean)
prec <- tapply(clim$NIEDERSCHLAGSHOEHE, clim$month, mean)
library(berryFunctions)
climateGraph(temp, prec, main="Potsdam 1893:2015")
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.
The DWD station IDs can be obtained from station names with
## Potsdam
## 3987
findID("Koeln", exactmatch=FALSE)
## Warning: in rdwd::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 function documentation contains an overview of the FTP folder structure.
If you find rdwd:::fileIndex 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:
# all files at a given path, with current file index (RCurl required):
links <- selectDWD(res="monthly", var="more_precip", per="hist", current=TRUE)
fileIndex is created with the function indexDWD used in meta.R.
# recursively list files on the FTP-server:
files <- indexDWD("hourly/sun") # use dir="some_path" to save the output elsewhere
berryFunctions::headtail(files, 5, na=TRUE)
# with other FTP servers, this should also work...
funet <- indexDWD(base="ftp.funet.fi/pub/standards/RFC/ien", folder="")
p <- RCurl::getURL("ftp.funet.fi/pub/standards/RFC/ien/",
verbose=T, ftp.use.epsv=TRUE, dirlistonly=TRUE)
TOC
File selection
selectDWD is designed to be very flexible:
# inputs can be vectorized, and period can be abbreviated:
selectDWD(c("Potsdam","Wuerzburg"), res="hourly", var="sun", per="hist")
## [[1]]
## [1] "ftp://ftp-cdc.dwd.de/pub/CDC/observations_germany/climate/hourly/sun/historical/ stundenwerte_SD_03987_18930101_20151231_hist.zip"
##
## [[2]]
## [1] "ftp://ftp-cdc.dwd.de/pub/CDC/observations_germany/climate/hourly/sun/historical/ stundenwerte_SD_05705_19510101_20151231_hist.zip"
# Time period can be doubled to get both filenames:
selectDWD("Potsdam", res="daily", var="kl", per="rh", outvec=TRUE)
## [1] "ftp://ftp-cdc.dwd.de/pub/CDC/observations_germany/climate/daily/kl/recent/ tageswerte_KL_03987_akt.zip"
## [2] "ftp://ftp-cdc.dwd.de/pub/CDC/observations_germany/climate/daily/kl/historical/ tageswerte_03987_18930101_20151231_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.
lapply(selectDWD(id=c(3467,5116)), substr, 58, 1e4)
## Warning: in rdwd::selectDWD: in file index 'fileIndex', there are 4 files
## with ID 3467.
## Warning: in rdwd::selectDWD: in file index 'fileIndex', there are 2 files
## with ID 5116.
## [[1]]
## [1] "/daily/more_precip/historical/tageswerte_RR_03467_19930601_20151231_hist.zip"
## [2] "/daily/more_precip/recent/tageswerte_RR_03467_akt.zip"
## [3] "/monthly/more_precip/historical/monatswerte_RR_03467_19930601_20151231_hist.zip"
## [4] "/monthly/more_precip/recent/monatswerte_RR_03467_akt.zip"
##
## [[2]]
## [1] "/daily/more_precip/historical/tageswerte_RR_05116_19930101_20061231_hist.zip"
## [2] "/monthly/more_precip/historical/monatswerte_RR_05116_19920701_20061231_hist.zip"
TOC