rdwd (version 1.8.0)

readDWD.raster: read dwd gridded raster data

Description

Read gridded raster data. Intended to be called via readDWD().
Note that R.utils must be installed to unzip the .asc.gz files.

Usage

readDWD.raster(file, gargs = NULL, dividebyten, quiet = rdwdquiet(), ...)

Value

terra::rast object

Arguments

file

Name of file on harddrive, like e.g. DWDdata/grids_germany/seasonal/air_temperature_mean/ 16_DJF_grids_germany_seasonal_air_temp_mean_188216.asc.gz

gargs

Named list of arguments passed to R.utils::gunzip(). The internal defaults are: remove=FALSE (recommended to keep this so file does not get deleted) and skip=TRUE (which reads previously unzipped files as is). If file has changed, use gargs=list(temporary=TRUE). The gunzip default destname means that the unzipped file is stored at the same path as file. DEFAULT gargs: NULL

dividebyten

Logical: Divide the numerical values by 10? See readDWD. DEFAULT: TRUE

quiet

Ignored. DEFAULT: FALSE through rdwdquiet()

...

Further arguments passed to terra::rast()

Author

Berry Boessenkool, , Dec 2018

See Also

readDWD()

Examples

if (FALSE)  # Excluded from CRAN checks, but run in localtests

rasterbase <- paste0(gridbase,"/seasonal/air_temperature_mean")
ftp.files <- indexFTP("/16_DJF", base=rasterbase, dir=tempdir())
localfiles <- dataDWD(ftp.files[1:2], base=rasterbase, joinbf=TRUE,
                      dir=locdir(), read=FALSE)
rf <- readDWD(localfiles[1])
rf <- readDWD(localfiles[1]) # runs faster at second time due to skip=TRUE
terra::plot(rf)

plotRadar(rf, proj="seasonal", extent=NULL)

testthat::expect_equal(c(terra::minmax(rf)), c(-8.2,4.4))
rf10 <- readDWD(localfiles[1], dividebyten=FALSE)
terra::plot(rf10)
testthat::expect_equal(c(terra::minmax(rf10*1)), c(-82,44))