The CF Metadata Conventions define a large number of standard names for physical parameters, including axes and data variables. This class accesses the standard names table. For each of the entries in the table two properties are provided: the canonical unit and a description. These properties are retrieved when searching for a given name.
Access to this class is through the CF environment. Use the
CF$standard_names$find("name_of_interest") method to access a particular
standard name. It is strongly recommended not to instantiate this class
manually as that may introduce problems with accessing the underlying XML
file.
The XML table is retrieved from the CF Metadata Conventions web site
here and stored locally in
the cache of the ncdfCF package. A check is performed periodically for an
updated version, which will then be downloaded automatically. The frequency
of the update check can be controlled with the
CF.options$cache_stale_days option.
Methods
Method new()
Initialize an instance of this class. This is done automatically when the package is loaded.
Usage
CFStandardNames$new()Method print()
Print the version number of the standard names table in use, if it is loaded. The table is loaded automatically when it is first used.
Method find()
Retrieve the information on the specified names.
Method load()
Load the standard names table so that it's contents may be used in display and analysis. Note that the table may be downloaded (4.3MB at version 91) if not available or stale.