NCGroup: NetCDF group
In ncdfCF: Easy Access to NetCDF Files with CF Metadata Conventions
NCGroup R Documentation
NetCDF group
Description
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
ncdfCF::NCObject -> NCGroup
Public fields
parentParent group of this group, the owning CFDataset for the
root group.
subgroupsList of child NCGroup instances of this group.
NCvarsList of netCDF variables that are located in this group.
NCdimsList of netCDF dimensions that are located in this group.
NCudtsList 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?
nameSet 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.
CFSet or retrieve the CFGroup that is associated with this
NC group.
Methods
Public methods
-
-
-
-
-
-
-
-
-
-
-
-
Inherited methods
Method new()
Create a new instance of this class.
Usage
NCGroup$new(id, name, attributes = data.frame(), parent, resource)
Arguments
idThe identifier of the group. If NA, the new group will be
created in the netCDF resource, unless argument parent == NULL, i.e.
the root group which already exists.
nameThe name of the group.
attributesOptional, a data.frame with group attributes.
parentThe parent group of this group. If NULL then argument
resource must be a valid instance of NCResource.
resourceOptional. Reference to the NCResource instance that
provides access to the netCDF resource.
Returns
An instance of this class.
Method print()
Summary of the group printed to the console.
Usage
NCGroup$print(stand_alone = TRUE, ...)
Arguments
stand_aloneLogical 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.
Method 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$find_by_name(name)
Arguments
nameThe name of an object, with an optional absolute or relative
group path from the calling group. The object must be an NC group,
dimension or variable.
Returns
The object with the provided name. If the object is not found,
returns NULL.
Method find_dim_by_id()
Find an NC dimension object by its id. Given the id of a
dimension, return the NCDimension object to the caller. The dimension
has to be found in the current group or any of its parents.
Usage
NCGroup$find_dim_by_id(id)
Arguments
idThe id of the dimension.
Returns
The NCDimension object with an identifier equal to the id
argument. If the object is not found, returns NULL.
Method has_name()
Has a given name been defined in this group already?
Usage
NCGroup$has_name(name)
Arguments
nameCharacter string. The name will be searched for, regardless
of case.
Returns
TRUE if name is present in the group, FALSE otherwise.
Method set_name()
Change the name of the NC group. The new name must be
valid and should not duplicate a sibling group.
Usage
NCGroup$set_name(new_name)
Arguments
new_nameThe new name for the NC group.
Returns
Self, invisibly.
Method unused()
Find NC variables that are not referenced by CF objects. For
debugging purposes only.
Usage
NCGroup$unused()
Returns
List of NCVariable.
Method create_group()
Create a new group as a sub-group of the current group. This
writes the new group to the netCDF resource, but only if it is open for
writing.
Usage
NCGroup$create_group(CFgroup)
Arguments
CFgroupThe CFGroup associated with this NC group.
Returns
The newly created group as a NCGroup instance, invisibly.
Method append()
Append an object to this group.
Usage
NCGroup$append(obj)
Arguments
objThe object to append. This must be an NCVariable or
NCDimension instance. Any other type of object will generate a
warning.
Returns
Self, invisible.
Method fullnames()
This method lists the fully qualified name of this group,
optionally including names in subgroups.
Usage
NCGroup$fullnames(recursive = TRUE)
Arguments
recursiveShould subgroups be scanned for names too (default is
TRUE)?
Returns
A character vector with group names.
Method 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$dimensions(scope = "all")
Arguments
scopeCharacter string that indicates if only dimensions in the
current group should be reported (local) or visible dimensions in
parent groups as well (all, default).
Returns
A vector of NCDimension objects.
Method clone()
The objects of this class are cloneable with this method.
Usage
NCGroup$clone(deep = FALSE)
Arguments
deepWhether to make a deep clone.
ncdfCF documentation built on Jan. 24, 2026, 1:08 a.m.
R Package Documentation
Browse R Packages
We want your feedback!
Note that we can't provide technical support on individual packages. You should contact the package authors for that.
| NCGroup | R Documentation |
NetCDF group
Description
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
ncdfCF::NCObject -> NCGroup
Public fields
parentParent group of this group, the owning
CFDatasetfor the root group.subgroupsList of child
NCGroupinstances of this group.NCvarsList of netCDF variables that are located in this group.
NCdimsList of netCDF dimensions that are located in this group.
NCudtsList 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?
nameSet 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.
CFSet or retrieve the CFGroup that is associated with this NC group.
Methods
Public methods
Inherited methods
Method new()
Create a new instance of this class.
Usage
NCGroup$new(id, name, attributes = data.frame(), parent, resource)
Arguments
idThe identifier of the group. If
NA, the new group will be created in the netCDF resource, unless argumentparent == NULL, i.e. the root group which already exists.nameThe name of the group.
attributesOptional, a
data.framewith group attributes.parentThe parent group of this group. If
NULLthen argumentresourcemust be a valid instance ofNCResource.resourceOptional. Reference to the NCResource instance that provides access to the netCDF resource.
Returns
An instance of this class.
Method print()
Summary of the group printed to the console.
Usage
NCGroup$print(stand_alone = TRUE, ...)
Arguments
stand_aloneLogical 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.
Method 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$find_by_name(name)
Arguments
nameThe name of an object, with an optional absolute or relative group path from the calling group. The object must be an NC group, dimension or variable.
Returns
The object with the provided name. If the object is not found,
returns NULL.
Method find_dim_by_id()
Find an NC dimension object by its id. Given the id of a dimension, return the NCDimension object to the caller. The dimension has to be found in the current group or any of its parents.
Usage
NCGroup$find_dim_by_id(id)
Arguments
idThe id of the dimension.
Returns
The NCDimension object with an identifier equal to the id
argument. If the object is not found, returns NULL.
Method has_name()
Has a given name been defined in this group already?
Usage
NCGroup$has_name(name)
Arguments
nameCharacter string. The name will be searched for, regardless of case.
Returns
TRUE if name is present in the group, FALSE otherwise.
Method set_name()
Change the name of the NC group. The new name must be valid and should not duplicate a sibling group.
Usage
NCGroup$set_name(new_name)
Arguments
new_nameThe new name for the NC group.
Returns
Self, invisibly.
Method unused()
Find NC variables that are not referenced by CF objects. For debugging purposes only.
Usage
NCGroup$unused()
Returns
List of NCVariable.
Method create_group()
Create a new group as a sub-group of the current group. This writes the new group to the netCDF resource, but only if it is open for writing.
Usage
NCGroup$create_group(CFgroup)
Arguments
CFgroupThe CFGroup associated with this NC group.
Returns
The newly created group as a NCGroup instance, invisibly.
Method append()
Append an object to this group.
Usage
NCGroup$append(obj)
Arguments
objThe object to append. This must be an
NCVariableorNCDimensioninstance. Any other type of object will generate a warning.
Returns
Self, invisible.
Method fullnames()
This method lists the fully qualified name of this group, optionally including names in subgroups.
Usage
NCGroup$fullnames(recursive = TRUE)
Arguments
recursiveShould subgroups be scanned for names too (default is
TRUE)?
Returns
A character vector with group names.
Method 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$dimensions(scope = "all")
Arguments
scopeCharacter string that indicates if only dimensions in the current group should be reported (
local) or visible dimensions in parent groups as well (all, default).
Returns
A vector of NCDimension objects.
Method clone()
The objects of this class are cloneable with this method.
Usage
NCGroup$clone(deep = FALSE)
Arguments
deepWhether to make a deep clone.
R Package Documentation
Browse R Packages
We want your feedback!
Note that we can't provide technical support on individual packages. You should contact the package authors for that.
Embedding an R snippet on your website
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.