cfdm.FieldAncillary

---

class cfdm.FieldAncillary(properties=None, data=None, source=None, copy=True, _use_data=True)

Bases: cfdm.mixin.netcdf.NetCDFVariable, cfdm.mixin.propertiesdata.PropertiesData, cfdm.core.fieldancillary.FieldAncillary

A field ancillary construct of the CF data model.

The field ancillary construct provides metadata which are distributed over the same sampling domain as the field itself. For example, if a data variable holds a variable retrieved from a satellite instrument, a related ancillary data variable might provide the uncertainty estimates for those retrievals (varying over the same spatiotemporal domain).

The field ancillary construct consists of an array of the ancillary data, which is zero-dimensional or which depends on one or more of the domain axes, and properties to describe the data. It is assumed that the data do not depend on axes of the domain which are not spanned by the array, along which the values are implicitly propagated. CF-netCDF ancillary data variables correspond to field ancillary constructs. Note that a field ancillary construct is constrained by the domain definition of the parent field construct but does not contribute to the domain’s definition, unlike, for instance, an auxiliary coordinate construct or domain ancillary construct.

NetCDF interface

The netCDF variable name may be accessed with the nc_set_variable, nc_get_variable, nc_del_variable and nc_has_variable methods.

The netCDF variable group structure may be accessed with the nc_set_variable, nc_get_variable, nc_variable_groups, nc_clear_variable_groups and nc_set_variable_groups methods.

New in version (cfdm): 1.7.0

Initialisation

Parameters

properties: dict, optional

Set descriptive properties. The dictionary keys are property names, with corresponding values. Ignored if the source parameter is set.

Properties may also be set after initialisation with the set_properties and set_property methods.

Parameter example:

properties={'standard_name': 'altitude'}

data: data_like, optional

Set the data. Ignored if the source parameter is set.

A data_like object is any object that can be converted to a Data object, i.e. numpy array_like objects, Data objects, and cfdm instances that contain Data objects.

The data also may be set after initialisation with the set_data method.

source: optional

Initialise the properties and data from those of source.

Note that if source is a FieldAncillary instance then cfdm.FieldAncillary(source=source) is equivalent to source.copy().

copy: bool, optional

If False then do not deep copy input parameters prior to initialisation. By default arguments are deep copied.

Inspection

Methods

dump	A full description of the field ancillary construct.
identity	Return the canonical identity.
identities	Return all possible identities.

Attributes

construct_type

Return a description of the construct type.

Properties

Methods

del_property	Remove a property.
get_property	Return a property.
has_property	Whether a property has been set.
set_property	Set a property.
properties	Return all properties.
clear_properties	Remove all properties.
set_properties	Set properties.

Data

Methods

apply_masking	Apply masking as defined by the CF conventions.
del_data	Remove the data.
get_data	Return the data.
has_data	Whether or not the construct has data.
set_data	Set the data.
insert_dimension	Expand the shape of the data array.
squeeze	Remove size one axes from the data array.
transpose	Permute the axes of the data array.

Attributes

data	Return the data.
dtype	Data-type of the data elements.
ndim	The number of dimensions in the data array.
shape	A tuple of the data array’s dimension sizes.
size	The number of elements in the data array.

Miscellaneous

Methods

copy	Return a deep copy.
creation_commands	Return the commands that would create the construct.
equals	Whether two instances are the same.
has_bounds	Whether or not there are cell bounds.
uncompress	Uncompress the construct.
get_filenames	Return the name of the file or files containing the data.

NetCDF

Methods

nc_del_variable	Remove the netCDF variable name.
nc_get_variable	Return the netCDF variable name.
nc_has_variable	Whether the netCDF variable name has been set.
nc_set_variable	Set the netCDF variable name.

Groups

Methods

nc_variable_groups	Return the netCDF variable group hierarchy.
nc_clear_variable_groups	Remove the netCDF variable group hierarchy.
nc_set_variable_groups	Set the netCDF variable group hierarchy.

Special

Methods

__deepcopy__	Called by the copy.deepcopy function.
__getitem__	Return a subspace defined by indices.
__repr__	Called by the repr built-in function.
__str__	Called by the str built-in function.

Docstring substitutions

Methods

_docstring_special_substitutions	Return the special docstring substitutions.
_docstring_substitutions	Returns the substitutions that apply to methods of the class.
_docstring_package_depth	Returns the class {{package}} substitutions package depth.
_docstring_method_exclusions	Returns method names excluded in the class substitutions.