With this function a group is created in memory, i.e. not associated with a
netCDF resource on file. This can be used to prepare new CF objects before
writing them to file. Extracting data from a CFVariable
into a CFArray
instance will also create a virtual group.
makeVirtualGroup(id, name, fullname)
A VirtualGroup
instance.
The id of the group.
The name of the group.
The full path and name of the group.