CartesianDifferential¶

class
astropy.coordinates.
CartesianDifferential
(d_x, d_y=None, d_z=None, unit=None, xyz_axis=None, copy=True)[source]¶ Bases:
astropy.coordinates.BaseDifferential
Differentials in of points in 3D cartesian coordinates.
 Parameters
 d_x, d_y, d_z
Quantity
orarray
The x, y, and z coordinates of the differentials. If
d_x
,d_y
, andd_z
have different shapes, they should be broadcastable. If not quantities,unit
should be set. If onlyd_x
is given, it is assumed that it contains an array with the 3 coordinates stored alongxyz_axis
. unit
Unit
orstr
If given, the differentials will be converted to this unit (or taken to be in this unit if not given.
 xyz_axis
int
, optional The axis along which the coordinates are stored when a single array is provided instead of distinct
d_x
,d_y
, andd_z
(default: 0). copybool, optional
If
True
(default), arrays will be copied. IfFalse
, arrays will be references, though possibly broadcast to ensure matching shapes.
 d_x, d_y, d_z
Attributes Summary
Component ‘d_x’ of the Differential.
Return a vector array of the x, y, and z coordinates.
Component ‘d_y’ of the Differential.
Component ‘d_z’ of the Differential.
Methods Summary
from_cartesian
(other[, base])Convert the differential from 3D rectangular cartesian coordinates to the desired class.
get_d_xyz
([xyz_axis])Return a vector array of the x, y, and z coordinates.
to_cartesian
([base])Convert the differential to 3D rectangular cartesian coordinates.
transform
(matrix[, base, transformed_base])Transform differentials using a 3x3 matrix in a Cartesian basis.
Attributes Documentation

attr_classes
= {'d_x': <class 'astropy.units.quantity.Quantity'>, 'd_y': <class 'astropy.units.quantity.Quantity'>, 'd_z': <class 'astropy.units.quantity.Quantity'>}¶

d_x
¶ Component ‘d_x’ of the Differential.

d_xyz
¶ Return a vector array of the x, y, and z coordinates.

d_y
¶ Component ‘d_y’ of the Differential.

d_z
¶ Component ‘d_z’ of the Differential.
Methods Documentation

classmethod
from_cartesian
(other, base=None)[source]¶ Convert the differential from 3D rectangular cartesian coordinates to the desired class.
 Parameters
 other
The object to convert into this differential.
 base
BaseRepresentation
The points for which the differentials are to be converted: each of the components is multiplied by its unit vectors and scale factors. Will be converted to
cls.base_representation
if needed.
 Returns
BaseDifferential
subclass instanceA new differential object that is this class’ type.

to_cartesian
(base=None)[source]¶ Convert the differential to 3D rectangular cartesian coordinates.
 Parameters
 baseinstance of
self.base_representation
The points for which the differentials are to be converted: each of the components is multiplied by its unit vectors and scale factors.
 baseinstance of
 Returns
CartesianDifferential
This object, converted.

transform
(matrix, base=None, transformed_base=None)[source]¶ Transform differentials using a 3x3 matrix in a Cartesian basis.
This returns a new differential and does not modify the original one.
 Parameters
 matrix(3,3) array_like
A 3x3 (or stack thereof) matrix, such as a rotation matrix.
 base, transformed_base
CartesianRepresentation
orNone
, optional Not used in the Cartesian transformation.