NetCDF group — NCGroup • ncdfCF

This class represents a netCDF group, the object that holds elements like dimensions and variables of a netCDF file.

Direct access to groups is usually not necessary. The principal objects of interest, CF data variables and axes, are accessible via CFGroup. Changing the properties of a netCDF group other than its name may very well invalidate the CF objects or even the netCDF file.

Super class

NCObject -> NCGroup

Public fields

parent: Parent group of this group, the owning CFDataset for the root group.
subgroups: List of child NCGroup instances of this group.
NCvars: List of netCDF variables that are located in this group.
NCdims: List of netCDF dimensions that are located in this group.
NCudts: List of netCDF user-defined types that are located in this group.

Active bindings

friendlyClassName: (read-only) A nice description of the class.
resource: (read-only) The RNetCDF object to the underlying netCDF resource.
handle: (read-only) Get the handle to the netCDF resource for the group
can_write: (read-only) Is the resource writable?
name: Set or retrieve the name of the group. Note that the name is always relative to the location in the hierarchy that the group is in and it should thus not be qualified by backslashes. The name has to be a valid CF name. The name of the root group cannot be changed.
fullname: (read-only) The fully qualified absolute path of the group.
root: (read-only) Retrieve the root group.
CF: Set or retrieve the CFGroup that is associated with this NC group.

Methods

Inherited methods

`NCGroup$new()`

Create a new instance of this class.

Usage

NCGroup$new(id, name, attributes = data.frame(), parent, resource)

Arguments

id: The identifier of the group. If NA, the new group will be created in the netCDF resource, unless argument parent == NULL, i.e. the root group which already exists.
name: The name of the group.
attributes: Optional, a data.frame with group attributes.
parent: The parent group of this group. If NULL then argument resource must be a valid instance of NCResource.
resource: Optional. Reference to the NCResource instance that provides access to the netCDF resource.

Returns

An instance of this class.

`NCGroup$print()`

Summary of the group printed to the console.

Usage

NCGroup$print(stand_alone = TRUE, ...)

Arguments

stand_alone: Logical to indicate if the group should be printed as an object separate from other objects (TRUE, default), or print as part of an enclosing object (FALSE).
...: Passed on to other methods.

`NCGroup$find_by_name()`

Find an object by its name. Given the name of an object, possibly preceded by an absolute or relative group path, return the object to the caller. Usually this method is called programmatically.

Usage

NCGroup$find_by_name(name)

Arguments

name: The name of an object, with an optional absolute or relative group path from the calling group. The object must be an NC group, dimension or variable. For dimensions, see also the find_dimension_by_name() method.

Returns

The object with the provided name. If the object is not found, returns NULL.

`NCGroup$find_dimvar_by_name()`

Find a dimension variable by its name. Dimensions are scoped differently than other out-of-group objects - specifically, dimensions are visible in all child groups. Given the name of a dimension variable, possibly preceded by an absolute or relative group path, return the dimension variable to the caller. Usually this method is called programmatically.

Usage

NCGroup$find_dimvar_by_name(name)

Arguments

name: The name of a dimension, with an optional absolute or relative group path from the calling group.

Returns

The dimension variable with the provided name. If the dimension variable is not found, returns NULL.

`NCGroup$find_dim_by_id()`

Find an NC dimension object by its id. Given the id of a dimension, return the NCDimension object to the caller. The dimension has to be found in the current group or any of its parents.

Usage

NCGroup$find_dim_by_id(id)

Arguments

id: The id of the dimension.

Returns

The NCDimension object with an identifier equal to the id argument. If the object is not found, returns NULL.

`NCGroup$has_name()`

Has a given name been defined in this group already?

Usage

NCGroup$has_name(name)

Arguments

name: Character string. The name will be searched for, regardless of case.

Returns

TRUE if name is present in the group, FALSE otherwise.

`NCGroup$set_name()`

Change the name of the NC group. The new name must be valid and should not duplicate a sibling group.

Usage

NCGroup$set_name(new_name)

Arguments

new_name: The new name for the NC group.

Returns

Self, invisibly.

`NCGroup$unused()`

Find NC variables that are not referenced by CF objects. For debugging purposes only.

Usage

NCGroup$unused()

Returns

List of NCVariable.

`NCGroup$create_group()`

Create a new group as a sub-group of the current group. This writes the new group to the netCDF resource, but only if it is open for writing.

Usage

NCGroup$create_group(CFgroup)

Arguments

CFgroup: The CFGroup associated with this NC group.

Returns

The newly created group as a NCGroup instance, invisibly.

`NCGroup$append()`

Append an object to this group.

Usage

NCGroup$append(obj)

Arguments

obj: The object to append. This must be an NCVariable or NCDimension instance. Any other type of object will generate a warning.

Returns

Self, invisible.

`NCGroup$fullnames()`

This method lists the fully qualified name of this group, optionally including names in subgroups.

Usage

NCGroup$fullnames(recursive = TRUE)

Arguments

recursive: Should subgroups be scanned for names too (default is TRUE)?

Returns

A character vector with group names.

`NCGroup$dimensions()`

List all the dimensions that are visible from this group, possibly including those that are defined in parent groups (by names not defined by any of their child groups in direct lineage to the current group).

Usage

NCGroup$dimensions(scope = "all")

Arguments

scope: Character string that indicates if only dimensions in the current group should be reported (local) or visible dimensions in parent groups as well (all, default).

Returns

A vector of NCDimension objects.

`NCGroup$clone()`

The objects of this class are cloneable with this method.

Usage

NCGroup$clone(deep = FALSE)

Arguments

deep: Whether to make a deep clone.