mHMr: pre- and post-prossesing for mHM

Description Usage Arguments Details Value Author(s) See Also Examples

mHM_extrapolNetCDF uses mHM_extrapolMat to extrapolate its matrix values in invalid and border location, e.g. originating from meteorological input fields for mHM (netCDF format).

1	mHM_extrapolNetCDF(netCDF, var, ext, return = FALSE)

`netCDF`	netCDF file name (full path).
`var`	character, name of variable to extrapolate.
`ext`	integer, radius (number of grid cells) within grid cells are extended, starting from border grid cells.
`return`	boolean, should extrapolated array be returned in console? default=FALSE

Runing mHM the first time for some netCDF products (e.g. Spain02, E-OBS) the warning no meteorological input available for whole simulation domain will be printed. This function extrapolates grids in invalid locations within a radius (number of grid cells) given by ext. Extrapolation is performed by a mean value of the surrounding cells of the invalid location.

Caution: netCDF input file will be overwritten, backup original file before use.

netCDF file

Johannes Brenner johannes.brenner@ufz.de

mHM_extrapolMat

# read netcdf file minimum air temperature for Júcar domain
 pkg_path <- path.package("mHMr")
 tmin_netcdf <- file.path(pkg_path, "data", "tmin.nc")

# open connection to netCDF
 tmin_op <-  RNetCDF::open.nc(tmin_netcdf)
# retrieve min. air temp  
 tmin <- RNetCDF::var.get.nc(tmin_op,"tmin")
# visualise original field
 image(tmin[,,1], zlim = c(2.5,4.5))

# extrapolate (radius: 1 grid cell)
 tmin_ext <- mHM_tmin_netcdf(netCDF = tmin_netcdf, vat = "tmin", ext = 1)
# visualise extrapolated field
 image(tmin_ext[,,1], zlim = c(2.5,4.5))