att.inq.nc: Inquire About a NetCDF Attribute

In RNetCDF: Interface to NetCDF Datasets

Description

Inquire about a NetCDF attribute.

Usage

att.inq.nc(ncfile, variable, attribute)

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 attribute's variable or "NC_GLOBAL" for a global attribute.
attribute	Either the ID or the name of the attribute to be inquired.

Details

This function returns information about a NetCDF attribute. Information about an attribute include its ID, its name, its type, and its length. The valid external NetCDF data types are NC_BYTE, NC_CHAR, NC_SHORT, NC_INT, NC_FLOAT, and NC_DOUBLE. In general, attributes are rather accessed by name than by their ID (which is called number) because the attribute number is more volatile than the name, since it can change when other attributes of the same variable are deleted.

Value

A list containing the following components:

id	Attribute ID.
name	Attribute name.
type	External NetCDF data type.
length	Length of this attribute.

Author(s)

Pavel Michna

References

http://www.unidata.ucar.edu/software/netcdf/

Examples

##  Create a new NetCDF dataset and define two dimensions
nc <- create.nc("att.inq.nc")

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))

##  Put some attributes
att.put.nc(nc, "temperature", "missing_value", "NC_DOUBLE", -99999.9)
att.put.nc(nc, "NC_GLOBAL", "title", "NC_CHAR", "Data from Foo")

##  Inquire about these attributes
att.inq.nc(nc, "temperature", "missing_value")
att.inq.nc(nc, "NC_GLOBAL", "title")

close.nc(nc)

Example output

$id
[1] 0

$name
[1] "missing_value"

$type
[1] "NC_DOUBLE"

$length
[1] 1

$id
[1] 0

$name
[1] "title"

$type
[1] "NC_CHAR"

$length
[1] 13

RNetCDF documentation built on May 2, 2019, 6:12 p.m.