NDDataArray¶
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class
astropy.nddata.
NDDataArray
(*arg, **kwd)[source] [edit on github]¶ Bases:
astropy.nddata.NDArithmeticMixin
,astropy.nddata.NDSlicingMixin
,astropy.nddata.NDIOMixin
,astropy.nddata.NDData
An
NDData
object with arithmetic. This class is functionally equivalent toNDData
in astropy versions prior to 1.0.The key distinction from raw numpy arrays is the presence of additional metadata such as uncertainties, a mask, units, flags, and/or a coordinate system.
Parameters: The actual data contained in this
NDData
object. Not that this will always be copies by reference , so you should make copy thedata
before passing it in if that’s the desired behavior.uncertainty :
NDUncertainty
, optionalUncertainties on the data.
mask :
ndarray
-like, optionalMask for the data, given as a boolean Numpy array or any object that can be converted to a boolean Numpy array with a shape matching that of the data. The values must be
False
where the data is valid andTrue
when it is not (like Numpy masked arrays). Ifdata
is a numpy masked array, providingmask
here will causes the mask from the masked array to be ignored.flags :
ndarray
-like orFlagCollection
, optionalFlags giving information about each pixel. These can be specified either as a Numpy array of any type (or an object which can be converted to a Numpy array) with a shape matching that of the data, or as a
FlagCollection
instance which has a shape matching that of the data.wcs : undefined, optional
WCS-object containing the world coordinate system for the data.
Warning
This is not yet defind because the discussion of how best to represent this class’s WCS system generically is still under consideration. For now just leave it as None
meta :
dict
-like object, optionalMetadata for this object. “Metadata” here means all information that is included with this object but not part of any other attribute of this particular object. e.g., creation date, unique identifier, simulation parameters, exposure time, telescope name, etc.
unit :
UnitBase
instance or str, optionalThe units of the data.
Raises: ValueError :
If the
uncertainty
ormask
inputs cannot be broadcast (e.g., match shape) ontodata
.Attributes Summary
dtype
numpy.dtype
of this object’s data.flags
mask
ndim
integer dimensions of this object’s data shape
shape tuple of this object’s data. size
integer size of this object’s data. uncertainty
unit
Methods Summary
convert_unit_to
(unit[, equivalencies])Returns a new NDData
object whose values have been converted to a new unit.Attributes Documentation
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dtype
¶ numpy.dtype
of this object’s data.
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flags
¶
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mask
¶
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ndim
¶ integer dimensions of this object’s data
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shape
¶ shape tuple of this object’s data.
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size
¶ integer size of this object’s data.
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uncertainty
¶
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unit
¶
Methods Documentation
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convert_unit_to
(unit, equivalencies=[])[source] [edit on github]¶ Returns a new
NDData
object whose values have been converted to a new unit.Parameters: unit :
astropy.units.UnitBase
instance or strThe unit to convert to.
equivalencies : list of equivalence pairs, optional
A list of equivalence pairs to try if the units are not directly convertible. See Equivalencies.
Returns: result :
NDData
The resulting dataset
Raises: UnitsError
If units are inconsistent.
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