# cf.DomainAxis¶

class cf.DomainAxis(size=None, source=None, copy=True)[source]

Bases: cfdm.domainaxis.DomainAxis

A domain axis construct of the CF data model.

A domain axis construct specifies the number of points along an independent axis of the domain. It comprises a positive integer representing the size of the axis. In CF-netCDF it is usually defined either by a netCDF dimension or by a scalar coordinate variable, which implies a domain axis of size one. The field construct’s data array spans the domain axis constructs of the domain, with the optional exception of size one axes, because their presence makes no difference to the order of the elements.

NetCDF interface

The netCDF dimension name of the construct may be accessed with the nc_set_dimension, nc_get_dimension, nc_del_dimension and nc_has_dimension methods.

Initialisation

Parameters
size: int, optional

The size of the domain axis.

The size may also be set after initialisation with the set_size method.

Parameter example:

size=192

source: optional

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

All other parameters, apart from copy, are ignored and their values are instead inferred from source by assuming that it has the DomainAxis 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 DomainAxis instance then cf.DomainAxis(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

 identity Return the canonical identity. identities Return all possible identities.

Attributes

 construct_type Return a description of the construct type.

## Size¶

Methods

 del_size Remove the size. has_size Whether the size has been set. get_size Return the size. set_size Set the size.

Attributes

 size The domain axis size.

## Miscellaneous¶

Methods

 copy Return a deep copy. creation_commands Returns the commands to create the domain axis construct. equals Whether two domain axis constructs are the same. inspect Inspect the object for debugging.

## NetCDF¶

Methods

 nc_del_dimension Remove the netCDF dimension name. nc_get_dimension Return the netCDF dimension name. nc_has_dimension Whether the netCDF dimension name has been set. nc_set_dimension Set the netCDF dimension name. nc_is_unlimited Inspect the unlimited status of the a netCDF dimension. nc_set_unlimited Set the unlimited status of the a netCDF dimension.

## Arithmetic and comparison operations¶

Arithmetic, bitwise and comparison operations are defined on a field construct as element-wise operations on its data which yield a new field construct or, for augmented assignments, modify the field construct’s data in-place.

Comparison operators

 __lt__ The rich comparison operator < __le__ The rich comparison operator <= __eq__ The rich comparison operator == __ne__ The rich comparison operator != __gt__ The rich comparison operator > __ge__ The rich comparison operator >=

Binary arithmetic operators

 __add__ The binary arithmetic operation + __sub__ The binary arithmetic operation -

Binary arithmetic operators with reflected (swapped) operands

 __radd__ The binary arithmetic operation + with reflected operands.

Augmented arithmetic assignments

 __iadd__ The augmented arithmetic assignment += __isub__ The augmented arithmetic assignment -=

Unary arithmetic operators

 __int__ Implements the built-in function int.

### Groups¶

Methods

 nc_dimension_groups Return the netCDF dimension group hierarchy. nc_clear_dimension_groups Remove the netCDF dimension group hierarchy. nc_set_dimension_groups Set the netCDF dimension group hierarchy.

## Special¶

Methods

 __deepcopy__ Called by the copy.deepcopy function. __hash__ Returns the hash value of the domain axis. __repr__ Called by the repr built-in function. __str__ Called by the str built-in function.