LogSpiral

class gammapy.astro.population.LogSpiral

Bases: object

Logarithmic spiral.

Reference: http://en.wikipedia.org/wiki/Logarithmic_spiral

Methods Summary

radius(self, theta, spiralarm_index)	Radius for a given angle.
theta(self, radius, spiralarm_index)	Angle for a given radius.
xy_position(self[, theta, radius, …])	Compute (x, y) position for a given angle or radius.

Methods Documentation

radius(self, theta, spiralarm_index)

Radius for a given angle.

Parameters:

theta : array_like

Angle (deg)

spiralarm_index : int

Spiral arm index

Returns:

radius : array_like

Radius (kpc)

theta(self, radius, spiralarm_index)

Angle for a given radius.

Parameters:

radius : array_like

Radius (kpc)

spiralarm_index : int

Spiral arm index

Returns:

theta : array_like

Angle (deg)

xy_position(self, theta=None, radius=None, spiralarm_index=0)

Compute (x, y) position for a given angle or radius.

Parameters:

theta : array_like

Angle (deg)

radius : array_like

Radius (kpc)

spiralarm_index : int

Spiral arm index

Returns:

x, y : array_like

Position (x, y)