PhysicsSphericalRepresentation¶
-
class
astropy.coordinates.
PhysicsSphericalRepresentation
(phi, theta=None, r=None, differentials=None, copy=True)[source]¶ Bases:
astropy.coordinates.BaseRepresentation
Representation of points in 3D spherical coordinates (using the physics convention of using
phi
andtheta
for azimuth and inclination from the pole).- Parameters
- phi, theta
Quantity
or str The azimuth and inclination of the point(s), in angular units. The inclination should be between 0 and 180 degrees, and the azimuth will be wrapped to an angle between 0 and 360 degrees. These can also be instances of
Angle
. Ifcopy
is False,phi
will be changed inplace if it is not between 0 and 360 degrees.- r
Quantity
The distance to the point(s). If the distance is a length, it is passed to the
Distance
class, otherwise it is passed to theQuantity
class.- differentialsdict,
PhysicsSphericalDifferential
, optional Any differential classes that should be associated with this representation. The input must either be a single
PhysicsSphericalDifferential
instance, or a dictionary of of differential instances with keys set to a string representation of the SI unit with which the differential (derivative) is taken. For example, for a velocity differential on a positional representation, the key would be's'
for seconds, indicating that the derivative is a time derivative.- copybool, optional
If
True
(default), arrays will be copied. IfFalse
, arrays will be references, though possibly broadcast to ensure matching shapes.
- phi, theta
Attributes Summary
The azimuth of the point(s).
The distance from the origin to the point(s).
The elevation of the point(s).
Methods Summary
from_cartesian
(cart)Converts 3D rectangular cartesian coordinates to spherical polar coordinates.
norm
(self)Vector norm.
represent_as
(self, other_class[, …])Convert coordinates to another representation.
scale_factors
(self)Scale factors for each component’s direction.
to_cartesian
(self)Converts spherical polar coordinates to 3D rectangular cartesian coordinates.
unit_vectors
(self)Cartesian unit vectors in the direction of each component.
Attributes Documentation
-
attr_classes
= {'phi': <class 'astropy.coordinates.angles.Angle'>, 'r': <class 'astropy.units.quantity.Quantity'>, 'theta': <class 'astropy.coordinates.angles.Angle'>}¶
-
phi
¶ The azimuth of the point(s).
-
r
¶ The distance from the origin to the point(s).
-
theta
¶ The elevation of the point(s).
Methods Documentation
-
classmethod
from_cartesian
(cart)[source]¶ Converts 3D rectangular cartesian coordinates to spherical polar coordinates.
-
norm
(self)[source]¶ Vector norm.
The norm is the standard Frobenius norm, i.e., the square root of the sum of the squares of all components with non-angular units. For spherical coordinates, this is just the absolute value of the radius.
- Returns
- norm
astropy.units.Quantity
Vector norm, with the same shape as the representation.
- norm
-
represent_as
(self, other_class, differential_class=None)[source]¶ Convert coordinates to another representation.
If the instance is of the requested class, it is returned unmodified. By default, conversion is done via cartesian coordinates.
- Parameters
- other_class
BaseRepresentation
subclass The type of representation to turn the coordinates into.
- differential_classdict of
BaseDifferential
, optional Classes in which the differentials should be represented. Can be a single class if only a single differential is attached, otherwise it should be a
dict
keyed by the same keys as the differentials.
- other_class
-
scale_factors
(self)[source]¶ Scale factors for each component’s direction.
Given unit vectors \(\hat{e}_c\) and scale factors \(f_c\), a change in one component of \(\delta c\) corresponds to a change in representation of \(\delta c \times f_c \times \hat{e}_c\).
- Returns
- scale_factorsdict of
Quantity
The keys are the component names.
- scale_factorsdict of
-
to_cartesian
(self)[source]¶ Converts spherical polar coordinates to 3D rectangular cartesian coordinates.
-
unit_vectors
(self)[source]¶ Cartesian unit vectors in the direction of each component.
Given unit vectors \(\hat{e}_c\) and scale factors \(f_c\), a change in one component of \(\delta c\) corresponds to a change in representation of \(\delta c \times f_c \times \hat{e}_c\).
- Returns
- unit_vectorsdict of
CartesianRepresentation
The keys are the component names.
- unit_vectorsdict of