cfdm.CellMeasure

---

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

Bases: cfdm.mixin.netcdf.NetCDFVariable, cfdm.mixin.netcdf.NetCDFExternal, cfdm.mixin.propertiesdata.PropertiesData, cfdm.core.cellmeasure.CellMeasure

A cell measure construct of the CF data model.

A cell measure construct provides information that is needed about the size or shape of the cells and that depends on a subset of the domain axis constructs. Cell measure constructs have to be used when the size or shape of the cells cannot be deduced from the dimension or auxiliary coordinate constructs without special knowledge that a generic application cannot be expected to have.

The cell measure construct consists of a numeric array of the metric data which spans a subset of the domain axis constructs, and properties to describe the data. The cell measure construct specifies a “measure” to indicate which metric of the space it supplies, e.g. cell horizontal areas, and must have a units property consistent with the measure, e.g. square metres. It is assumed that the metric does not depend on axes of the domain which are not spanned by the array, along which the values are implicitly propagated. CF-netCDF cell measure variables correspond to cell measure constructs.

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.

New in version (cfdm): 1.7.0

Initialisation

Parameters

measure: str, optional

Set the measure that indicates the metric given by the data array. Ignored if the source parameter is set.

The measure may also be set after initialisation with the set_measure method.

Parameter example:

measure='area'

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': 'cell_area'}

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 measure, properties and data from those of source.

Note that if source is a CellMeasure instance then cfdm.CellMeasure(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 cell measure construct.
identity	Return the canonical identity.
identities	Return all possible identities.

Attributes

construct_type

Return a description of the construct type.

Properties

Methods

del_measure	Remove the measure.
get_measure	Return the measure.
has_measure	Whether the measure has been set.
set_measure	Set the measure.
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	Returns the commands to create the cell measure construct.
equals	Whether two cell measure constructs 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.
nc_get_external	Whether a construct matches an external netCDF variable.
nc_set_external	Set external status of a netCDF variable.

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.