var.inq.nc {RNetCDF} | R Documentation |
Inquire About a NetCDF Variable
Description
Inquire about a NetCDF variable.
Usage
var.inq.nc(ncfile, variable)
Arguments
ncfile |
Object of class NetCDF which points to the NetCDF dataset (as returned from open.nc ).
|
variable |
Either the ID or the name of the variable to be inquired.
|
Details
This function returns information about a NetCDF variable, including its name, ID, type, number of dimensions, a vector of the dimension IDs, and the number of attributes.
Value
A list of named components, some of which are only included for datasets in "netcdf4"
format (as reported by file.inq.nc
).
id |
Variable ID.
|
name |
Variable name.
|
type |
External NetCDF data type as one of the following labels: NC_BYTE , NC_UBYTE , NC_CHAR , NC_SHORT , NC_USHORT , NC_INT , NC_UINT , NC_INT64 , NC_UINT64 , NC_FLOAT , NC_DOUBLE , NC_STRING , or a user-defined type name.
|
ndims |
Number of dimensions the variable was defined as using.
|
dimids |
Vector of dimension IDs corresponding to the variable dimensions (NA for scalar variables). Order is leftmost varying fastest.
|
natts |
Number of variable attributes assigned to this variable.
|
chunksizes |
("netcdf4" ) Chunk size expressed as the number of elements along each dimension, in the same order as dimids . NULL implies contiguous storage.
|
cache_bytes |
("netcdf4" ) Size of chunk cache in bytes (NULL if unsupported).
|
cache_slots |
("netcdf4" ) The number of slots in the chunk cache (NULL if unsupported).
|
cache_preemption |
("netcdf4" ) A value between 0 and 1 (inclusive) that biases the cache scheme towards eviction of chunks that have been fully read (NULL if unsupported).
|
deflate |
("netcdf4" ) Integer indicating level of compression, from 0 (minimum) to 9 (maximum), or NA if compression is not enabled.
|
shuffle |
("netcdf4" ) TRUE if byte shuffling is enabled for the variable, FALSE otherwise.
|
big_endian |
("netcdf4" ) Byte order of the variable. TRUE for big-endian, FALSE for little-endian, NA for not yet determined, or NULL if unsupported.
|
fletcher32 |
("netcdf4" ) TRUE if the fletcher32 checksum is enabled for this variable, FALSE otherwise.
|
szip_options |
("netcdf4" ) Integer containing a bitmask of szip options. NA if szip is not used, or NULL if unsupported.
|
szip_bits |
("netcdf4" ) Number of bits per pixel for szip. NA if szip is not used, or NULL if unsupported.
|
filter_id |
("netcdf4" ) Vector of filter IDs associated with the variable, or NULL if the NetCDF library does not support the multi-filter interface.
|
filter_params |
("netcdf4" ) List with one element per filter_id , or NULL if the NetCDF library does not support the multi-filter interface. Each list member is a vector of numeric parameters for the corresponding filter. Please see the NetCDF documentation for information about the available filters and their parameters.
|
Author(s)
Pavel Michna, Milton Woods
References
https://www.unidata.ucar.edu/software/netcdf/
Examples
## Create a new NetCDF dataset and define two dimensions
file1 <- tempfile("var.inq_", fileext=".nc")
nc <- create.nc(file1)
dim.def.nc(nc, "station", 5)
dim.def.nc(nc, "time", unlim=TRUE)
## Create two variables, one as coordinate variable
var.def.nc(nc, "time", "NC_INT", "time")
var.def.nc(nc, "temperature", "NC_DOUBLE", c(0,1))
## Inquire about these variables
var.inq.nc(nc, 0)
var.inq.nc(nc, "temperature")
close.nc(nc)
unlink(file1)
[Package
RNetCDF version 2.9-2
Index]