CartesianDifferential¶

class astropy.coordinates.CartesianDifferential(d_x, d_y=None, d_z=None, unit=None, xyz_axis=None, copy=True)[source]

Differentials in of points in 3D cartesian coordinates.

Parameters
d_x, d_y, d_z

The x, y, and z coordinates of the differentials. If d_x, d_y, and d_z have different shapes, they should be broadcastable. If not quantities, unit should be set. If only d_x is given, it is assumed that it contains an array with the 3 coordinates stored along xyz_axis.

unitUnit or str

If given, the differentials will be converted to this unit (or taken to be in this unit if not given.

xyz_axisint, optional

The axis along which the coordinates are stored when a single array is provided instead of distinct d_x, d_y, and d_z (default: 0).

copybool, optional

If True (default), arrays will be copied. If False, arrays will be references, though possibly broadcast to ensure matching shapes.

Attributes Summary

 attr_classes 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 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.

Parameters
xyz_axisint, optional

The axis in the final array along which the x, y, z components should be stored (default: 0).

Returns
d_xyzQuantity

With dimension 3 along xyz_axis. Note that, if possible, this will be a view.

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.

baseBaseRepresentation

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 instance

A new differential object that is this class’ type.

get_d_xyz(xyz_axis=0)[source]

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

Parameters
xyz_axisint, optional

The axis in the final array along which the x, y, z components should be stored (default: 0).

Returns
d_xyzQuantity

With dimension 3 along xyz_axis. Note that, if possible, this will be a view.

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.

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_baseCartesianRepresentation or None, optional

Not used in the Cartesian transformation.