cfdm.FieldAncillary


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

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 True (the default) deep copy input parameters prior to initialisation. If False arguments are not 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

array

A numpy array deep copy of the data.

data

Return the data.

datetime_array

An independent numpy array of date-time objects.

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.

to_memory

Bring data on disk into memory.

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.