AxisymmetricPlummerModel#

jeanspy.model.AxisymmetricPlummerModel

See methods and properties for individual lookup pages, or the alphabetical API dictionary to search all classes. The full class contract and existing member anchors are retained below.

class jeanspy.model.AxisymmetricPlummerModel(re_pc, q=1.0)[source]#

Bases: jeanspy.axisymmetric.AxisymmetricStellarModel

Unit-integral spheroidal Plummer tracer (re_pc is equatorial scale).

Notes

Inputs and units. re_pc is equatorial scale in pc, q>0 is intrinsic axis ratio. Intrinsic R>=0 and signed z, or signed sky x/y, are finite and broadcast to one shape (pc).

Returns and shape. density(R,z) is pc^-3; radial_derivative is dnu/dR in pc^-4; surface_density(x, y, inclination) is pc^-2; projected_axis_ratio returns sqrt(cos(i)^2+q^2 sin(i)^2). Array outputs follow the broadcast shape, including scalar output.

Validity. x is the line of nodes; i=0 is face-on. re_pc and q are positive finite scalars. This tracer has a finite central density.

Errors. Invalid scales, coordinates or inclination raise ValueError. This component supplies densities and their radial derivative; it does not calculate forces or velocity moments.

Backend. NumPy/SciPy CPU, frozen dataclasses.

Differentiation. No physical-parameter automatic differentiation on this API.

Examples. examples/docs_axisymmetric.py

Parameters:

re_pc (float)
q (float)

re_pc: float#

q: float = 1.0#

density(R, z)[source]#

Return the unit-normalized tracer density in pc^-3.

Cylindrical coordinates R>=0 and signed z are in pc and broadcast. Nonfinite, empty or negative-R inputs raise ValueError.

radial_derivative(R, z)[source]#

Return d(nu)/dR in pc^-4 at cylindrical coordinates R,z in pc.

Coordinates broadcast; R must be nonnegative and both arrays finite and nonempty. Invalid coordinates raise ValueError through density.

projected_axis_ratio(inclination)[source]#

Return the dimensionless projected minor-to-major tracer axis ratio.

Inclination is a scalar in radians; zero is face-on. It must be finite and in [0, pi/2], otherwise ValueError is raised.

surface_density(x, y, inclination)[source]#

Project the unit-normalized tracer onto signed sky coordinates.

x and y are finite, nonempty, broadcastable coordinates in pc; inclination is a scalar angle in radians within the class domain. Returns pc^-2 with the broadcast shape. Invalid coordinates or inclination raise ValueError.

density_3d(R_pc, z_pc)[source]#: Return unit-normalized tracer density in pc^-3 at coordinates in pc.