read_ncdf: Read Data from a NetCDF
In jonasbhend/myhelpers: Set of Tools for Often Performed Tasks

Description Usage Arguments Details Note See Also

read_ncdf reads and collates (a slice of) data from a single netcdf file or a collection of netcdf files. read_single is the underlying function that does the heavy lifting on the single files (not exported, for programming purposes only). get_fcfiles assembles the available forecast files for a collection of forecasts (e.g. for a specific index, grid, granularity, and bias correction method). Reading subsets of NetCDF files allows you to subset the file by longitude and latitude, by grid index, by time, or as a compact representation of a selection of grid points (e.g. land only).

read_ncdf(x, ..., expand = FALSE, n.cores = 1)

read_single(x, index = NA, lon = NULL, lat = NULL, loi = NULL,
  lai = NULL, mask = NULL, tlim = NULL, ti = NULL, time = NULL)

get_fcfiles(model = "ecmwf-system4", grid = "global2", index = "tas",
  method = "none", init = "05", granularity = "monthly",
  source = c("euporias", "operational", "demo"))

`x`	a vector of file paths to the forecast file collection
`...`	parameters passed on to `read_single`
`expand`	logical, should forecast arrays be expanded if differing numbers of ensemble members are available in hindcast set?
`n.cores`	number of cores for parallelization
`index`	Variable name to be read
`lon, lat`	the longitude and latitude to be read for point forecasts, or the longitude and latitude limits for a subset of the forecast domain
`loi, lai`	the grid indices to be read (alternative to `lon, lat`)
`mask`	logical vector with grid point indices to be read (see details).
`tlim`	vector of start and end dates to be read.
`ti`	time indices to be read
`time`	vector of dates to be read. The comparison is performed on on the same format as `time` (i.e. if `is.Date(time)`, the comparison is done transforming the ncdf time to `as.Date`)
`model`	Name of forecasting system
`grid`	Name of grid to be read
`method`	Name of method for debiasing of forecast
`init`	Month of initialization (e.g. '05')
`granularity`	granularity of forecast data to be read
`source`	where should forecasts be retrieved from (see details)?

Alternatives are for the forecasts to be retrieved from the research directory (source = 'euporias') or from the direcotry with operational forecasts (source = 'operational'). In the latter case, the grid, method, and granularity arguments are void as these will always be set to native, none and monthly respectively.

Reading in subsets only works for continous subset not wrapping around the domain. That is, for data on a global grid with positive longitudes, a European domain cannot be extracted.

read_single

jonasbhend/myhelpers documentation built on May 19, 2019, 7:27 p.m.