cf.Field

class cf.Field(properties={}, attributes={}, data=None, domain=None, flags=None, ancillary_variables=None, axes=None, auto_cyclic=True, copy=True)

Bases: cf.variable.Variable

A field construct according to the CF data model.

A field is a container for a data array and metadata comprising properties to describe the physical nature of the data and a coordinate system (called a domain) which describes the positions of each element of the data array.

The field’s domain may contain dimensions and auxiliary coordinate and cell measure objects (which themselves contain data arrays and properties to describe them) and coordinate reference objects.

All components of a field are optional.

Miscellaneous

Field objects are picklable.

Initialization

Parameters:

properties : dict, optional

Provide the new field with CF properties from the dictionary’s key/value pairs.

data : cf.Data, optional

Provide the new field with an N-dimensional data array in a cf.Data object.

domain : cf.Domain, optional

Provide the new field with a coordinate system in a cf.Domain object. By default an empty domain is created.

attributes : dict, optional

Provide the new field with attributes from the dictionary’s key/value pairs.

flags : cf.Flags, optional

Provide the new field with self-describing flag values in a cf.Flags object.

ancillary_variables : cf.AncillaryVariables, optional

Provide the new field with ancillary variable fields in a cf.AncillaryVariables object.

axes : sequence of str, optional

A list of domain axis identifiers ('dimN'), stating the axes, in order, of field’s data array. By default these axis identifiers will be the sequence of consecutive axis identifiers 'dim0' up to 'dimM', where M is the number of axes of the data array, or an empty sequence if the data array is a scalar.

If an axis of the data array already exists in the domain then the it must have the same size as the domain axis. If it does not exist in the domain then a new axis will be created.

By default the axes will either be those defined for the data array by the domain or, if these do not exist, the domain axis identifiers whose sizes unambiguously match the data array.

auto_cyclic : bool, optional

If False then do not auto-detect cyclic axes. By default cyclic axes are auto-detected with the setcyclic method.

copy : bool, optional

If False then do not deep copy arguments prior to initialization. By default arguments are deep copied.

Field CF Properties

add_offset	The add_offset CF property.
calendar	The calendar CF property.
cell_methods	The cf.CellMethods object containing the CF cell methods of the data array.
comment	The comment CF property.
Conventions	The Conventions CF property.
_FillValue	The _FillValue CF property.
flag_masks	The flag_masks CF property.
flag_meanings	The flag_meanings CF property.
flag_values	The flag_values CF property.
history	The history CF property.
institution	The institution CF property.
leap_month	The leap_month CF property.
leap_year	The leap_year CF property.
long_name	The long_name CF property.
missing_value	The missing_value CF property.
month_lengths	The month_lengths CF property.
references	The references CF property.
scale_factor	The scale_factor CF property.
source	The source CF property.
standard_error_multiplier	The standard_error_multiplier CF property.
standard_name	The standard_name CF property.
title	The title CF property.
units	The units CF property.
valid_max	The valid_max CF property.
valid_min	The valid_min CF property.
valid_range	The valid_range CF property.

Field attributes

ancillary_variables	A cf.AncillaryVariables object containing CF ancillary data.
array	A numpy array deep copy of the data array.
attributes	A dictionary of the attributes which are not CF properties.
data	The cf.Data object containing the data array.
day	The day of each data array element.
domain	The cf.Domain object containing the field’s domain.
dtarray	An independent numpy array of date-time objects.
dtvarray	A numpy array view the data array converted to date-time objects.
dtype	The numpy data type of the data array.
Flags	A cf.Flags object containing self-describing CF flag values.
hardmask	Whether the mask is hard (True) or soft (False).
hour	The hour of each data array element.
isscalar	True if and only if the data array is a scalar array.
mask	A field containing the mask of the data array.
minute	The minute of each data array element.
month	The month of each data array element.
ndim	Number of dimensions in the data array.
properties	A dictionary of the CF properties.
rank	The number of axes in the domain of the field.
second	The second of each data array element.
shape	Tuple of the data array’s dimension sizes.
size	Number of elements in the data array.
subspace	Return a new object which will get or set a subspace of the field.
unique	The unique elements of the array.
Units	The cf.Units object containing the units of the data array.
varray	A numpy array view of the data array.
year	The year of each data array element.

Field methods

allclose	Returns True if two broadcastable fields have have equal array values to within numerical tolerance.
anchor	Roll a cyclic axis so that the given value lies in the first coordinate cell.
asdatetime	Change the internal representation of data array elements from numeric reference times to datatime-like objects.
asreftime	Change the internal representation of data array elements from datatime-like objects to numeric reference times.
aux	Return an auxiliary coordinate object of the domain, or its domain identifier.
auxs	Return auxiliary coordinate objects of the domain.
axes	Return domain axis identifiers from the field.
axes_sizes	Return the size a of a domain axis.
axis	Return a domain axis identifier.
axis_name	Return the canonical name for an axis.
axis_size	Return the size a of a domain axis.
binary_mask	Return a binary (0 and 1) missing data mask of the data array.
ceil	Return the ceiling of the data array.
chunk	Partition the data array.
clip	Clip (limit) the values in the data array in place.
close	Close all files referenced by the field.
collapse	Collapse axes of the field.
coord	Return a dimension or auxiliary coordinate object of the domain, or its domain identifier.
coords	Return dimension and auxiliary coordinate objects of the domain.
copy	Return a deep copy.
cos	Take the trigonometric cosine of the data array.
cyclic	Set the cyclicity of an axis.
data_axes	Return the domain axes identifiers of the field’s data array.
datum	Return an element of the data array as a standard Python scalar.
delattr	Delete a named attribute.
delprop	Delete a CF property.
dim	Return a dimension coordinate object of the domain, or its domain identifier.
dims	Return dimension coordinate objects of the domain.
dump	Return a string containing a description of the field.
equals	True if two fields are logically equal, False otherwise.
equivalent	True if and only if two fields are logically equivalent.
equivalent_data	Return True if two fields have equivalent data arrays.
equivalent_domain	Return True if two fields have equivalent data domains.
expand_dims	Insert a size 1 axis into the data array.
fill_value	Return the data array missing data value.
flip	Flip (reverse the direction of) axes of the field.
floor	Return the floor of the data array.
getattr	Get a named attribute.
getprop	Get a CF property.
hasattr	Return whether an attribute exists.
hasprop	Return True if a CF property exists, otherise False.
identity	Return the variable’s identity.
indices	Create data array indices based on domain metadata.
insert_aux	Insert an auxiliary coordinate object into the domain in place.
insert_axis	Insert an axis into the domain in place.
insert_data	Insert a new data array into the field in place.
insert_dim	Insert a dimension coordinate object into the domain in place.
insert_measure	Insert an cell measure object into the domain in place.
insert_ref	Insert a coordinate reference object into the domain in place.
iscyclic	Whether or not a particular axis is cyclic.
item	Return an item, or its domain identifier, from the field.
item_axes	Return the axes of a domain item of the field.
items	Return domain items from the field.
items_axes	Return the axes of domain items of the field.
iter	Return a single element iterable for the output of a method (with arguments).
mask_invalid	Mask the array where invalid values occur (NaNs or infs).
max	The maximum of the data array.
mean	The unweighted mean the data array.
match	Test whether or not the field satisfies the given conditions.
measure	Return a cf.CellMeasure object of the domain, or its domain identifier.
measures	Return cell measure objects of the domain.
method	Return the results of a callable method (with arguments) applied to the field.
mid_range	The unweighted average of the maximum and minimum of the data array.
min	The minimum of the data array.
name	Return a name for the variable.
override_units	Override the data array units in place.
period	Return the period of a potentially cyclic axis.
range	The absolute difference between the maximum and minimum of the data array.
ref	Return a coordinate reference object of the domain, or its domain identifier.
refs	Return coordinate references of the domain.
remove_axes	Remove and return axes from the field.
remove_axis	Remove and return an axis from the field.
remove_data	Remove and return the data array of the field.
remove_item	Remove and return a domain item from the field.
remove_items	Remove and return domain items from the domain.
rint	Round elements of the data array to the nearest integer.
roll	Roll the field along a cyclic axis.
sample_size	The number of non-missing data elements in the data array.
sd	The unweighted sample standard deviation of the data array.
select	Return the field if it satisfies the given conditions.
setattr	Set a named attribute.
setcyclic	Set axes to be cyclic if they meet conditions.
setprop	Set a CF property.
sin	Take the trigonometric sine of the data array.
sort	Sort of the field in place.
squeeze	Remove size 1 axes from the data array.
subspace	Return a new object which will get or set a subspace of the field.
sum	The sum of the data array.
transpose	Permute the axes of the data array in place.
trunc	Return the truncated values of the data array.
unsqueeze	Insert size 1 axes into the data array of the field.
var	The unweighted sample variance of the data array.
weights	Return weights for the data array values.
where	Set data array elements depending on a condition.

Field class methods

concatenate

Join a sequence of fields together.

Field arithmetic and comparison operations

See the section on arithmetic and comparison operations.

Field special methods

Standard library functions

__deepcopy__

Used if copy.deepcopy is called.

Container customization

__len__	The built-in function len
__getitem__	x.__getitem__(index) <==> x[index]
__contains__	Membership test operator in

String representations

__repr__	The built-in function repr
__str__	The built-in function str