get.ncdf: Load Subsets of NetCDF Files By Location, Run, Time
In ks905383/quantproj: Project Climate Data Based on Changes in Distribution Shape

Description Usage Arguments Value Expected File Structure Warnings and Notes on File Structure

get.ncdf loads the data stored in NetCDF files, as determined by the information in process.inputs.tmp, output from get.process.chunks. Data is loaded by region, latitude band, run, and time range, and is concatenated across files if necessary. Data is returned as a list by pixel, with every list member containing the lat and lon of the pixel, and the raw data ("Raw").

1	get.ncdf(defaults, process.inputs.tmp, year.range = numeric())

`defaults`	the output from `set.defaults`. The defaults used are `filevar` and `varnames` to search for grid/run variablesin the files.
`process.inputs.tmp`	the output from `get.process.chunks`, giving the information needed to load a chunk of data from NetCDF file(s), including filename(s), locations within files, etc.
`year.range`	which year range should be output, in a vector `c(year_i,year_f)`. If nothing set, the full possible year range of the file is loaded.

A list; each element reperesenting a pixel, containing named subelements lat, lon, and the raw data Raw.

In general, most common forms of climate file structures are supported, especially the CMIP5 structure. Variables can either be on a lon x lat grid or stored by linear location. Files can either contain all runs of a model or can be saved by run. Files can either contain the whole timeframe of a model run or be split up in consecutive temporal chunks. Furthermore:

filename: the code searches for NetCDF files using the search string "[defaults$filevar]_day_.*nc" (by default; this can be changed by setting defaults$search.str). Make sure no other NetCDF files with that pattern are present in the search directory (by default defaults$mod.data.dir).
variable setup: Currently, the code expects the primary variable to have either a location dimension (giving the linear index of a location), or a lon x lat grid. These are all identified by name - the search terms used can be set in defaults$varnames - out-of-the-box, the package for example supports "lat", "latitude", "Latitude", and "latitude_1" as possible names for the "lat" dimension.
locations: The code expects there to be two location variables, lat and lon (CMIP5 syntax), giving the lat/lon location of every pixel in the file. The names of those variables can be any of the alternatives given by defaults$varnames.
multiple runs: If there are multiple runs in the file, there should be a run variable/dimension in the file giving the run id as an integer

Files have to begin on 01/01 and end on 12/31 of a year.
Loading speeds up a lot if as much of the data as possible is stored in a single file - an example is storing files by region, but with all runs and years in the same file for the pixels in that region.

ks905383/quantproj documentation built on Nov. 1, 2020, 9:12 p.m.