rdwd: climate data from the German Weather Service
2017-01-24
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.
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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, here’s a manual workaround that might work for most functions: On the github package page, click on Clone or Download -> Download ZIP (topright, link), unzip the file to some place, then
setwd("that/path")
dd <- dir("rdwd-master/R", full=T)
dummy <- sapply(dd, source)
This creates all R functions as objects in your globalenv workspace (and overwrites existing objects of the same name!).
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Basic usage
tdir <- tempdir()
link <- selectDWD("Potsdam", res="daily", var="kl", per="recent")
file <- dataDWD(link, read=FALSE, dir=tdir)
## rdwd::dirDWD: adding to directory 'C:/Users/berry/AppData/Local/Temp/RtmpEDyaiK'
## rdwd::dataDWD: 1 file already existing and not downloaded again: 'daily_kl_recent_tageswerte_KL_03987_akt.zip'
## Now downloading 0 files...
## rdwd::fileDWD: Creating 1 file: 'daily_kl_recent_tageswerte_KL_03987_akt.zip'
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: "2015-07-23" "2015-07-24" ...
## $ QUALITAETS_NIVEAU : int 3 3 3 3 3 3 3 3 3 3 ...
## $ LUFTTEMPERATUR : num 19.4 20.5 20.3 16.3 16.1 16.6 15.8 15.4 14.6 18.4 ...
## $ DAMPFDRUCK : num 15.9 15 15.8 11 14.5 14.2 11.1 11.3 10.5 10.5 ...
## $ BEDECKUNGSGRAD : num 5.6 4.6 5.9 5.8 7 6 4.4 5.3 4.2 4.3 ...
## $ LUFTDRUCK_STATIONSHOEHE : num 1003 1002 991 999 991 ...
## $ REL_FEUCHTE : num 72.2 65 67.6 60.9 79.2 ...
## $ WINDGESCHWINDIGKEIT : num 3.4 3.3 6.9 6.3 4.3 5.9 5.8 7 4.3 3.3 ...
## $ LUFTTEMPERATUR_MAXIMUM : num 23.4 26.4 26.7 21.2 22.2 20 21.4 19.8 19.6 26.8 ...
## $ LUFTTEMPERATUR_MINIMUM : num 14.5 14.7 12.8 13.1 12.4 14 12.4 11.8 10.7 10 ...
## $ LUFTTEMP_AM_ERDB_MINIMUM: num 12.9 12.7 12.7 12 12 12.9 10 9.3 7.7 7 ...
## $ WINDSPITZE_MAXIMUM : num 8.6 9.3 22.7 19.1 14.4 17.7 17.3 17 10.7 7.8 ...
## $ NIEDERSCHLAGSHOEHE : num 0 3.4 1.1 0.2 3.9 0 0.1 0.4 0 0 ...
## $ NIEDERSCHLAGSHOEHE_IND : int 0 6 6 6 6 6 6 6 0 0 ...
## $ SONNENSCHEINDAUER : num 6.82 9.87 6.18 7.97 1.87 ...
## $ 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 ...
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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)
## rdwd::dirDWD: creating directory 'S:/Dropbox/Public/rdwd/vignettes/DWDdata'
## rdwd::fileDWD: Creating 1 file: 'monthly_kl_historical_monatswerte_03987_18930101_20151231_hist.zip'
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)
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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
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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.
head(rdwd:::fileIndex) # 28'798 rows in Jan 2017 (with some almost duplicate files)
## res var per id start end
## 1 daily kl historical
## 2 daily kl historical
## 3 daily kl historical
## 4 daily kl historical 00001 19370101 19860630
## 5 daily kl historical 00003 18910101 20110331
## 6 daily kl historical 00044 19710301 20151231
## path
## 1 /daily/kl/historical/BESCHREIBUNG_obsgermany_climate_daily_kl_historical_de.pdf
## 2 /daily/kl/historical/DESCRIPTION_obsgermany_climate_daily_kl_historical_en.pdf
## 3 /daily/kl/historical/KL_Tageswerte_Beschreibung_Stationen.txt
## 4 /daily/kl/historical/tageswerte_00001_19370101_19860630_hist.zip
## 5 /daily/kl/historical/tageswerte_00003_18910101_20110331_hist.zip
## 6 /daily/kl/historical/tageswerte_00044_19710301_20151231_hist.zip
If you find this 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 at https://github.com/brry/rdwd/blob/master/R/meta.R#L185.
# 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)
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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 al 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"
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