ncdfvdfcreate - Generate a VDF metadata file for a NetCDF data set
ncdfvdfcreate [options] ncdf_files... vdffile
ncdfvdfcreate generates a .vdf metafile that defines a VAPOR Data Collection (VDC) suitable for containing a collection of data contained in one or more NetCDF files. The command expects that data contained in the list of NetCDF input files to be the result of a single simulation. I.e. the same coordinates and dimensions are used by all files.
Thus, the command treats a collection of NetCDF files as a single, time-varying data set containing 2D and 3D spatial variables defined at a specified timestep, independent of which netCDF file contains the data.
The netCDF variables may be "explicitly" time-varying: the slowest varying dimension may correspond to time, while the remaining dimensions correspond to space. Or the variables may be implicitly time-varying, possessing no explicit time dimension, in which case the time index of a variable is determined by file ordering. For example, if the variable "v" is found in the files "a.nc" and "b.nc" and nowhere else, and "a.nc" preceeds "b.nc" in the list of files provided to the class constructor, then a.nc is assumed to contain "v" at time step 0, and "b.nc" contains "v" at time step 1.
The command understands the Arakawa C-Grid ("staggered" variables), and can interpolate them onto a common (unstaggered) grid.
Specifies the spatial dimensions of all 3D variables to be considered. The default is to use the dimensions of the first 3D variable encountered in the NetCDF files. The format of dimensions is NXxNYxNZ, where NX is the fastest varying dimension, NY the next fastest, and NZ the slowest.
A colon-delimited list of names of 2D and 3D (spatial) data variables to include in the .vdf file. In general, the list of variables should be a subset of the data variables found in the MOM/POP input files. If this option is not present the default behavior is to generate the list of variables from all of the 2D and 3D (spatial) variables found in any of the MOM/POP netCDF input files.
Name of netCDF attribute specifying missing value, if any.
Use this option if missing data locations may vary between time steps and/or variables. If this is unknown it is safest to use this option at the expense of increased storage requirements.
A colon-delimited list specifying the names of any staggered dimensions. A "staggered" dimension has dimension one greater than an unstaggered dimension. Variables defined on staggered grids are interpolated to unstaggered grids.
Integer offset of first time step in NetCDF files to be converted
Colon delimited list of time dimension variable names. Any dimension names listed with this option are considered time dimensions. Data variables whose slowest varying dimension is named by this option are considered time varying.
Colon delimited list of time coordinate variables. If this 1D variable is present, it specfies the time in user-defined units for each time step.
See vdfcreate.
See vdfcreate.
See vdfcreate.
This option is for VDC2 only, see vdfcreate.
This option is for VDC2 only, see vdfcreate.
Print a usage statement and then exit.
The command
ncdfvdfcreate -vars u:v:temp file1.nc file2.nc file3.nc mydata.vdfwill construct a VDF file, mydata.vdf that will contain the u, v, and temp variable names for all time steps found in the NetCDF files file1.nc, file2.nc, and file3.nc. Because no time dimension is specified the variables are assumed to be implicitly time varying (have no time dimension).
The command
ncdfvdfcreate -timedims times -vars u:v:temp file1.nc file2.nc file3.nc mydata.vdfis identical to the previous example, except that here the variables are expected to be explicitly time varying, having their slowest varying dimension named "times".
vdfcreate, ncdf2vdf.
Conversion of NetCDF datafiles to a VAPOR VDC
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