cf.AuxiliaryCoordinate

---

class cf.AuxiliaryCoordinate(properties=None, data=None, bounds=None, geometry=None, interior_ring=None, source=None, copy=True, _use_data=True)

Bases: cf.mixin.coordinate.Coordinate, cf.mixin.propertiesdatabounds.PropertiesDataBounds, cfdm.auxiliarycoordinate.AuxiliaryCoordinate

An auxiliary coordinate construct of the CF data model.

An auxiliary coordinate construct provides information which locate the cells of the domain and which depend on a subset of the domain axis constructs. Auxiliary coordinate constructs have to be used, instead of dimension coordinate constructs, when a single domain axis requires more then one set of coordinate values, when coordinate values are not numeric, strictly monotonic, or contain missing values, or when they vary along more than one domain axis construct simultaneously. CF-netCDF auxiliary coordinate variables and non-numeric scalar coordinate variables correspond to auxiliary coordinate constructs.

The auxiliary coordinate construct consists of a data array of the coordinate values which spans a subset of the domain axis constructs, an optional array of cell bounds recording the extents of each cell (stored in a Bounds object), and properties to describe the coordinates. An array of cell bounds spans the same domain axes as its coordinate array, with the addition of an extra dimension whose size is that of the number of vertices of each cell. This extra dimension does not correspond to a domain axis construct since it does not relate to an independent axis of the domain. Note that, for climatological time axes, the bounds are interpreted in a special way indicated by the cell method 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 netCDF UGRID node coordinate variable name may be accessed with the nc_set_node_coordinate_variable, nc_get_node_coordinate_variable, nc_del_node_coordinate_variable, and nc_has_node_coordinate_variable methods.

The netCDF UGRID node coordinate variable group structure may be accessed with the nc_set_node_coordinate_variable, nc_get_node_coordinate_variable, nc_variable_node_coordinate_groups, nc_clear_node_coordinate_variable_groups, and nc_set_node_coordinate_variable_groups methods.

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': 'latitude'}

data: data_like, optional

Set the data.

A data_like object is any object that can be converted to a Data object, i.e. numpy array_like objects, Data objects, and cf instances that contain Data objects.

The data also may be set after initialisation with the set_data method.

bounds: Bounds, optional

Set the bounds array.

The bounds array may also be set after initialisation with the set_bounds method.

geometry: str, optional

Set the geometry type.

The geometry type may also be set after initialisation with the set_geometry method.

Parameter example:

geometry='polygon'

interior_ring: InteriorRing, optional

Set the interior ring variable.

The interior ring variable may also be set after initialisation with the set_interior_ring method.

source: optional

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

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

direction	Return None, indicating that it is not specified whether the values are increasing or decreasing.
dump	A full description of the auxiliary coordinate construct.
identity	Return the canonical identity.
identities	Return all possible identities.

Attributes

construct_type	Return a description of the construct type.
id	An identity for the AuxiliaryCoordinate object.
ctype	The CF coordinate type.
T	True if and only if the data are coordinates for a CF ‘T’ axis.
X	True if and only if the data are coordinates for a CF ‘X’ axis.
Y	True if and only if the data are coordinates for a CF ‘Y’ axis.
Z	True if and only if the data are coordinates for a CF ‘Z’ axis.

Bounds

Methods

del_bounds	Remove the bounds.
get_bounds	Return the bounds.
has_bounds	Whether or not there are bounds.
set_bounds	Set the bounds.
get_bounds_data	Return the bounds data.
contiguous	Return True if a construct has contiguous cells.

Attributes

bounds	Return the bounds.
cellsize	The cell sizes.
lower_bounds	The lower bounds of cells.
upper_bounds	The upper bounds of cells.

Geometries

Methods

del_geometry	Remove the geometry type.
get_geometry	Return the geometry type.
has_geometry	True if there is a geometry type.
set_geometry	Set the geometry type.
del_interior_ring	Remove the geometry type.
get_interior_ring	Return the interior ring variable for polygon geometries.
has_interior_ring	Whether or not there is an interior ring variable.
set_interior_ring	Set the interior_ring.
del_node_count	Remove the node count variable for geometry bounds.
get_node_count	Return the node count variable for geometry bounds.
has_node_count	Whether geometry bounds have a node count variable.
set_node_count	Set the node count variable for geometry bounds.
del_part_node_count	Remove the part node count variable for geometry bounds.
get_part_node_count	Return the part node count variable for geometry bounds.
has_part_node_count	Whether geometry bounds have a part node count variable.
set_part_node_count	Set the part node count variable for geometry bounds.

Attributes

interior_ring

Return the interior ring variable for polygon geometries.

Climatology

Methods

del_climatology	Remove the climatology setting.
get_climatology	Return the climatology setting.
is_climatology	True if the coordinates are climatological.
set_climatology	Set whether or not coordinates are climatological.

Selection

Methods

match_by_identity	Determine whether or not a variable satisfies conditions.
match_by_naxes	Whether or not the data has a given dimensionality.
match_by_ncvar	Whether or not the netCDF variable name satisfies conditions.
match_by_property	Determine whether or not a variable satisfies conditions.
match_by_units	Whether or not the construct has given units.

Properties

Methods

del_property	Remove a property.
get_property	Get a CF 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.

Attributes

add_offset	The add_offset CF property.
axis	The axis CF property.
calendar	The calendar CF property.
comment	The comment CF property.
_FillValue	The _FillValue CF property.
history	The history 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.
positive	The positive CF property.
scale_factor	The scale_factor CF property.
standard_name	The standard_name 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.

Units

Methods

override_units	Override the units.
override_calendar	Override the calendar of date-time units.

Attributes

Units

The cf.Units object containing the units of the data array.

Data

Attributes

array	A numpy array deep copy of the data.
data	The Data object containing the data array.
datetime_array	An independent numpy array of date-time objects.
datum	Return an element of the data array as a standard Python scalar.
dtype	The numpy data type of the data array.
isscalar	True if the data array is scalar.
ndim	The number of data dimensions.
shape	A tuple of the data array’s dimension sizes.
size	The number of elements in the data.
varray	A numpy array view of the data.

Methods

to_dask_array	Convert the data to a dask array.
__getitem__	Return a subspace of the field construct defined by indices.
del_data	Remove the data.
get_data	Return the data.
has_data	Whether or not the construct has data.
set_data	Set the data.

Rearranging elements

flatten	Flatten axes of the data.
flip	Flip (reverse the direction of) data dimensions.
insert_dimension	Expand the shape of the data array.
roll	Roll the data along an axis.
squeeze	Remove size one axes from the data array.
swapaxes	Interchange two axes of an array.
transpose	Permute the axes of the data array.

Expanding the data

halo	Expand the data by adding a halo.
pad_missing	Pad an axis with missing data.

Data array mask

apply_masking	Apply masking as defined by the CF conventions.
count	Count the non-masked elements of the data.
count_masked	Count the masked elements of the data.
fill_value	Return the data array missing data value.
masked_invalid	Mask the array where invalid values occur (NaN or inf).

binary_mask	A binary (0 and 1) missing data mask of the data array.
hardmask	Whether the mask is hard (True) or soft (False).
mask	The mask of the data array.

Changing data values

__setitem__	Called to implement assignment to x[indices]
masked_invalid	Mask the array where invalid values occur (NaN or inf).
subspace	Return a new variable whose data is subspaced.
where	Set data array elements depending on a condition.

Cyclicity

Methods

autoperiod

Set the period of cyclicity where it can be determined.

Attributes

iscyclic	Whether or not a given axis is cyclic.
isperiodic	True if a given axis is periodic.

Miscellaneous

rechunk	Change the chunk structure of the data.
close	Close all files referenced by the construct.
convert_reference_time	Convert reference time data values to have new units.
cyclic	Get or set the cyclicity of axes of the data array.
period	Return or set the period for cyclic values.
get_original_filenames	The names of files containing the original data and metadata.
persist	Persist the underlying dask array into memory.

Miscellaneous

Methods

concatenate	Join a sequence of variables together.
copy	Return a deep copy.
creation_commands	Return the commands that would create the construct.
equals	Whether two instances are the same.
inspect	Inspect the object for debugging.
to_memory	Bring data on disk into memory.
uncompress	Uncompress the construct.

Mathematical operations

Methods

Trigonometrical and hyperbolic functions

arccos	Take the trigonometric inverse cosine of the data element- wise.
arccosh	Take the inverse hyperbolic cosine of the data element-wise.
arcsin	Take the trigonometric inverse sine of the data element-wise.
arcsinh	Take the inverse hyperbolic sine of the data element-wise.
arctan	Take the trigonometric inverse tangent of the data element- wise.
arctanh	Take the inverse hyperbolic tangent of the data element-wise.
cos	Take the trigonometric cosine of the data element-wise.
cosh	Take the hyperbolic cosine of the data element-wise.
sin	Take the trigonometric sine of the data element-wise.
sinh	Take the hyperbolic sine of the data element-wise.
tan	Take the trigonometric tangent of the data element-wise.
tanh	Take the hyperbolic tangent of the data element-wise.

Rounding and truncation

ceil	The ceiling of the data, element-wise.
clip	Limit the values in the data.
floor	Floor the data array, element-wise.
rint	Round the data to the nearest integer, element-wise.
round	Round the data to the given number of decimals.
trunc	Truncate the data, element-wise.

Statistical collapses

maximum	The maximum of the data array.
mean	The unweighted mean the data array.
mid_range	The unweighted average of the maximum and minimum of the data array.
minimum	The minimum of the data array.
range	The absolute difference between the maximum and minimum of the data array.
sample_size	The number of non-missing data elements in the data array.
sum	The sum of the data array.
standard_deviation	The unweighted sample standard deviation of the data array.
variance	The unweighted sample variance of the data array.

Exponential and logarithmic functions

exp	The exponential of the data, element-wise.
log	The logarithm of the data array.

Date-time operations

Attributes

day	The day of each date-time data array element.
datetime_array	An independent numpy array of date-time objects.
hour	The hour of each date-time data array element.
minute	The minute of each date-time data array element.
month	The month of each date-time data array element.
reference_datetime	The reference date-time of units of elapsed time.
second	The second of each date-time data array element.
year	The year of each date-time data array element.

Logic functions

Truth value testing

all	Test whether all data elements evaluate to True.
any	Test whether any data elements evaluate to True.

Comparison

allclose	Test whether all data are element-wise equal to other, broadcastable data.
equivalent	True if two constructs are equal, False otherwise.

Set operations

unique

The unique elements of 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_del_node_coordinate_variable	Remove the netCDF node coordinate variable name.
nc_get_node_coordinate_variable	Return the netCDF node coordinate variable name.
nc_has_node_coordinate_variable	Whether the netCDF node coordinate variable name is set.
nc_node_coordinate_variable_groups	Return the netCDF node coordinate variable group hierarchy.
nc_set_node_coordinate_variable	Set the netCDF node coordinate variable name.
nc_set_node_coordinate_variable_groups	Set the netCDF node_coordinate_variable group hierarchy.
nc_clear_node_coordinate_variable_groups	Remove the netCDF node coordinate variable group hierarchy.

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.

CFA

Methods

add_file_location	Add a new file location in-place.
cfa_clear_file_substitutions	Remove all of the CFA-netCDF file name substitutions.
cfa_del_file_substitution	Remove a CFA-netCDF file name substitution.
cfa_file_substitutions	Return the CFA-netCDF file name substitutions.
cfa_update_file_substitutions	Set CFA-netCDF file name substitutions.
del_file_location	Remove a file location in-place.
file_locations	The locations of files containing parts of the data.

Aliases

Methods

match	Alias for match_by_identity.
max	Alias for maximum.
min	Alias for minimum.
sd	Alias for standard_deviation
var	Alias for variance

Attributes

dtarray

Alias for datetime_array.

Arithmetic and comparison operations

Arithmetic, bitwise and comparison operations are defined as element-wise operations on the data, which yield a new construct or, for augmented assignments, modify the 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 -
__mul__	The binary arithmetic operation *
__div__	The binary arithmetic operation /
__truediv__	The binary arithmetic operation / (true division)
__floordiv__	The binary arithmetic operation //
__pow__	The binary arithmetic operations ** and pow
__mod__	The binary arithmetic operation %

Binary arithmetic operators with reflected (swapped) operands

__radd__	The binary arithmetic operation + with reflected operands.
__rsub__	The binary arithmetic operation - with reflected operands.
__rmul__	The binary arithmetic operation * with reflected operands.
__rdiv__	The binary arithmetic operation / with reflected operands.
__rtruediv__	The binary arithmetic operation / (true division) with reflected operands.
__rfloordiv__	The binary arithmetic operation // with reflected operands.
__rpow__	The binary arithmetic operations ** and pow with reflected operands.
__rmod__	The binary arithmetic operation % with reflected operands.

Augmented arithmetic assignments

__iadd__	The augmented arithmetic assignment +=
__isub__	The augmented arithmetic assignment -=
__imul__	The augmented arithmetic assignment *=
__idiv__	The augmented arithmetic assignment /=
__itruediv__	The augmented arithmetic assignment /= (true division)
__ifloordiv__	The augmented arithmetic assignment //=
__ipow__	The augmented arithmetic assignment **=
__imod__	The binary arithmetic operation %=

Unary arithmetic operators

__neg__	The unary arithmetic operation -
__pos__	The unary arithmetic operation +
__abs__	The unary arithmetic operation abs

Binary bitwise operators

__and__	The binary bitwise operation &
__or__	The binary bitwise operation |
__xor__	The binary bitwise operation ^
__lshift__	The binary bitwise operation <<
__rshift__	The binary bitwise operation >>

Binary bitwise operators with reflected (swapped) operands

__rand__	The binary bitwise operation & with reflected operands.
__ror__	The binary bitwise operation | with reflected operands.
__rxor__	The binary bitwise operation ^ with reflected operands.
__rlshift__	The binary bitwise operation << with reflected operands.
__rrshift__	The binary bitwise operation >> with reflected operands.

Augmented bitwise assignments

__iand__	The augmented bitwise assignment &=
__ior__	The augmented bitwise assignment |=
__ixor__	The augmented bitwise assignment ^=
__ilshift__	The augmented bitwise assignment <<=
__irshift__	The augmented bitwise assignment >>=

Unary bitwise operators

__invert__

The unary bitwise operation ~

Special

Methods

__contains__	Called to implement membership test operators.
__deepcopy__	Called by the copy.deepcopy function.
__getitem__	Return a subspace of the field construct defined by indices.
__repr__	Called by the repr built-in function.
__setitem__	Called to implement assignment to x[indices]
__str__	Called by the str built-in function.
__array__	Returns a numpy array representation of the data.
__data__	Returns a new reference to the data.
__query_isclose__	Query interface method for an “is close” condition.

Deprecated

Methods

asdatetime	Deprecated at version 3.0.0.
asreftime	Deprecated at version 3.0.0.
chunk	Partition the data array.
delprop	Deprecated at version 3.0.0, use method del_property instead.
expand_dims	Deprecated at version 3.0.0, use method insert_dimension instead.
files	Deprecated at version 3.4.0, consider using the get_original_filenames method instead.
get_filenames	Return the name of the file or files containing the data.
getprop	Deprecated at version 3.0.0, use method get_property instead.
hasprop	Deprecated at version 3.0.0, use method has_property instead.
insert_data	Deprecated at version 3.0.0, use set_data method instead.
mask_invalid	Mask the array where invalid values occur.
name	Deprecated at version 3.0.0, use method ‘identity’ instead.
remove_data	Deprecated at version 3.0.0, use method del_data instead.
select	Deprecated at version 3.0.0.
setprop	Deprecated at version 3.0.0, use method set_property instead.

Attributes

attributes	Deprecated at version 3.0.0.
Data	Deprecated at version 3.0.0, use data attribute or get_data method instead.
dtvarray	Deprecated at version 3.0.0.
hasbounds	Deprecated at version 3.0.0, use method has_bounds instead.
hasdata	Deprecated at version 3.0.0, use has_data method instead.
isauxiliary	Deprecated at version 3.7.0, use construct_type attribute instead.
isdimension	Deprecated at version 3.7.0, use construct_type attribute instead.
isdomainancillary	Deprecated at version 3.7.0, use construct_type attribute instead.
isfieldancillary	Deprecated at version 3.7.0, use construct_type attribute instead.
ismeasure	Deprecated at version 3.7.0, use construct_type attribute instead.
unsafe_array	Deprecated at version 3.0.0, use array attribute instead.