cfdm.Field

---

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

Bases: cfdm.mixin.netcdf.NetCDFVariable, cfdm.mixin.netcdf.NetCDFGeometry, cfdm.mixin.netcdf.NetCDFGlobalAttributes, cfdm.mixin.netcdf.NetCDFGroupAttributes, cfdm.mixin.netcdf.NetCDFComponents, cfdm.mixin.netcdf.NetCDFUnreferenced, cfdm.mixin.fielddomain.FieldDomain, cfdm.mixin.propertiesdata.PropertiesData, cfdm.mixin.files.Files, cfdm.core.field.Field

A field construct of the CF data model.

The field construct is central to the CF data model, and includes all the other constructs. A field corresponds to a CF-netCDF data variable with all of its metadata. All CF-netCDF elements are mapped to a field construct or some element of the CF field construct. The field construct contains all the data and metadata which can be extracted from the file using the CF conventions.

The field construct consists of a data array and the definition of its domain (that describes the locations of each cell of the data array), field ancillary constructs containing metadata defined over the same domain, and cell method constructs to describe how the cell values represent the variation of the physical quantity within the cells of the domain. The domain is defined collectively by the following constructs of the CF data model: domain axis, dimension coordinate, auxiliary coordinate, cell measure, coordinate reference and domain ancillary constructs.

The field construct also has optional properties to describe aspects of the data that are independent of the domain. These correspond to some netCDF attributes of variables (e.g. units, long_name and standard_name), and some netCDF global file attributes (e.g. history and institution).

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.

The selection of properties to be written as netCDF global attributes may be accessed with the nc_global_attributes, nc_clear_global_attributes, and nc_set_global_attribute methods.

The netCDF group attributes may be accessed with the nc_group_attributes, nc_clear_group_attributes, nc_set_group_attribute, and nc_set_group_attributes methods.

The netCDF geometry variable name and group structure may be accessed with the nc_set_geometry_variable, nc_get_geometry_variable, nc_geometry_variable_groups, nc_clear_variable_groups, and nc_set_geometry_variable_groups methods.

Some components exist within multiple constructs, but when written to a netCDF dataset the netCDF names associated with such components will be arbitrarily taken from one of them. The netCDF variable, dimension and sample dimension names and group structures for such components may be set or removed consistently across all such components with the nc_del_component_variable, nc_set_component_variable, nc_set_component_variable_groups, nc_clear_component_variable_groups, nc_del_component_dimension, nc_set_component_dimension, nc_set_component_dimension_groups, nc_clear_component_dimension_groups, nc_del_component_sample_dimension, nc_set_component_sample_dimension, nc_set_component_sample_dimension_groups, nc_clear_component_sample_dimension_groups methods.

CF-compliance issues for field constructs read from a netCDF dataset may be accessed with the dataset_compliance method.

New in version (cfdm): 1.7.0

Initialisation

Parameters

properties: dict, optional

Set descriptive properties. The dictionary keys are property names, with corresponding values.

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

Parameter example:

properties={'standard_name': 'air_temperature'}

source: optional

Convert source, which can be any type of object, to a Field instance.

All other parameters, apart from copy, are ignored and their values are instead inferred from source by assuming that it has the Field API. Any parameters that can not be retrieved from source in this way are assumed to have their default value.

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

copy: bool, optional

If True (the default) then deep copy the input parameters prior to initialisation. By default the parameters are not deep copied.

Inspection

Methods

dump	A full description of the field 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.
del_properties	Remove 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 of the field construct.
del_data_axes	Removes the keys of the axes spanned by the construct data.
get_data_axes	Gets the keys of the axes spanned by the construct data.
has_data_axes	Whether the axes spanned by the construct data have been set.
set_data_axes	Sets the axes spanned by the construct data.
insert_dimension	Expand the shape of the data array.
squeeze	Remove size one axes from the data.
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 data dimensions.
shape	A tuple of the data array’s dimension sizes.
size	The number elements in the data.

Metadata constructs

Methods

construct	Return a metadata construct.
construct_key	Return the identifier of a metadata construct.
construct_item	Return a metadata construct and its identifier.
del_construct	Remove a metadata construct.
get_construct	Return a metadata construct.
has_construct	Whether a unique metadata construct exists.
set_construct	Set a metadata construct.
domain_axis_key	Returns the domain axis key spanned by 1-d coordinates.
auxiliary_coordinate	Select an auxiliary coordinate construct.
auxiliary_coordinates	Return auxiliary coordinate constructs.
cell_connectivity	Select a cell connectivity construct.
cell_connectivities	Select cell connectivity constructs.
cell_measure	Select a cell measure construct.
cell_measures	Return cell measure constructs.
cell_method	Select a cell method construct.
cell_methods	Return cell method constructs.
coordinate	Select a dimension or auxiliary coordinate construct.
coordinates	Return dimension and auxiliary coordinate constructs.
coordinate_reference	Return a coordinate reference construct, or its key.
coordinate_references	Return coordinate reference constructs.
dimension_coordinate	Select a dimension coordinate construct.
dimension_coordinates	Return dimension coordinate constructs.
domain_ancillary	Select a domain ancillary construct.
domain_ancillaries	Return domain ancillary constructs.
domain_axis	Select a domain axis construct.
domain_axes	Return domain axis constructs.
domain_topology	Select a domain topology construct.
domain_topologies	Return domain topology constructs.
field_ancillary	Select a field ancillary construct.
field_ancillaries	Return field ancillary constructs.
climatological_time_axes	Return all axes which are climatological time axes.

Attributes

constructs

Return the metadata constructs.

Domain

Methods

get_domain

Return the domain.

Attributes

domain

Return the domain.

Miscellaneous

Methods

compress	Compress the field construct.
copy	Return a deep copy.
creation_commands	Return the commands that would create the field construct.
equals	Whether two constructs are the same.
convert	Convert a metadata construct into a new field construct.
has_bounds	Whether or not there are cell bounds.
has_geometry	Return whether or not any coordinates have cell geometries.
indices	Create indices that define a subspace of the field construct.
uncompress	Uncompress the field construct.
get_filenames	Return the names of the files containing the data.
get_original_filenames	The names of files containing the original data and metadata.
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.
nc_global_attributes	Returns properties to write as netCDF global attributes.
nc_clear_global_attributes	Removes properties to write as netCDF global attributes.
nc_set_global_attribute	Select a property to be written as a netCDF global attribute.
nc_set_global_attributes	Set properties to be written as netCDF global attributes.

Groups

Methods

nc_variable_groups	Return the netCDF variable group hierarchy.
nc_set_variable_groups	Set the netCDF variable group hierarchy.
nc_clear_variable_groups	Remove the netCDF variable group hierarchy.
nc_group_attributes	Returns properties to write as netCDF group attributes.
nc_clear_group_attributes	Removes properties to write as netCDF group attributes.
nc_set_group_attribute	Select a property to be written as a netCDF group attribute.
nc_set_group_attributes	Set properties to be written as netCDF group attributes.

Geometries

Methods

nc_del_geometry_variable	Remove the netCDF geometry container variable name.
nc_get_geometry_variable	Return the netCDF geometry container variable name.
nc_has_geometry_variable	Whether a netCDF geometry container variable has a name.
nc_set_geometry_variable	Set the netCDF geometry container variable name.
nc_geometry_variable_groups	Return the netCDF geometry variable group hierarchy.
nc_set_geometry_variable_groups	Set the netCDF geometry variable group hierarchy.
nc_clear_geometry_variable_groups	Remove the netCDF geometry variable group hierarchy.

Components

Methods

nc_del_component_variable	Remove the netCDF variable name of components.
nc_set_component_variable	Set the netCDF variable name for components.
nc_set_component_variable_groups	Set the netCDF variable groups of components.
nc_clear_component_variable_groups	Remove the netCDF variable groups of components.
nc_del_component_dimension	Remove the netCDF dimension name of components.
nc_set_component_dimension	Set the netCDF dimension name of components.
nc_set_component_dimension_groups	Set the netCDF dimension groups of components.
nc_clear_component_dimension_groups	Remove the netCDF dimension groups of components.
nc_del_component_sample_dimension	Remove the netCDF sample dimension name of components.
nc_set_component_sample_dimension	Set the netCDF sample dimension name of components.
nc_set_component_sample_dimension_groups	Set the netCDF sample dimension groups of components.
nc_clear_component_sample_dimension_groups	Remove the netCDF sample dimension groups of components.

Dataset compliance

Methods

dataset_compliance

Return the dataset compliance report.

Special

Methods

__deepcopy__	Called by the copy.deepcopy function.
__getitem__	Return a subspace of the field 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.