synthpop.position
=================

.. py:module:: synthpop.position

.. autoapi-nested-parse::

   This file includes the Position class.
   It handles the generation of star positions within a given cone.



Classes
-------

.. autoapisummary::

   synthpop.position.Position


Module Contents
---------------

.. py:class:: Position(coord_trans, **kwargs)

   Position class for a Population class.
   This contains methods to randomly generate positions within a field/slice,

   Attributes
   ----------
   l_deg : float [degree]
       Galactic longitude of the current field in degrees.
   l_rad : float [radian]
       Galactic longitude of the current field in radians.
   b_deg : float [degree]
       Galactic latitude of the current field in degrees.
   b_rad : float [radian]
       Galactic latitude of the current field in radians.
   cone_angle : float [radian]
       opening angle of the cone

   Methods
   -------
   __init__(l_deg: float, b_deg: float, solid_angle_sr: float) : None
       Initialize the Class
   update(*args, **kwargs) : None
       Update the class with new coordinates, passes arguments to __init__()
   draw_random_point_in_slice(dist_inner: float, dist_outer: float, N: int = 1): tuple
       generate N points within the slice
   rotate_00_to_lb(delta_l: ndarray, delta_b: ndarray) : Tuple[ndarray, ndarray]
       rotates a cone from pointing toward 0,0 to (l,b)


   .. py:attribute:: coord_trans


   .. py:attribute:: l_deg
      :value: None



   .. py:attribute:: l_rad
      :value: None



   .. py:attribute:: b_deg
      :value: None



   .. py:attribute:: b_rad
      :value: None



   .. py:attribute:: cone_angle
      :value: None



   .. py:method:: update_location(l_deg: float, b_deg: float, solid_angle: float)

      Set the location and solid_angle

      Parameters
      ----------
      l_deg, b_deg : float [deg]
          galactic longitude and latitude in degrees
      solid_angle : float [sr]
          size of the cone



   .. py:method:: draw_random_point_in_slice(dist_inner: float, dist_outer: float, n_stars: int = 1) -> Tuple[numpy.ndarray, numpy.ndarray, numpy.ndarray, numpy.ndarray, numpy.ndarray, numpy.ndarray]

      Draw one or more random point in a slice
      given coordinates (self.l, self.b) [degrees],
      solid angle[steradians], and distance range[kpc]

      To get distance d, we draw from a cumulative quadratic distribution. To do so,
      we found the integrated r**2 such that our CDF is
      Prob(x) = (x**3 - dist_inner**3)/(dist_outer**3 - dist_inner**3)
      Then, we invert for x(Prob) so that we can draw Prob from Uniform(0,1)
      x = ((r_max**3 - r_min**3)*Prob + r_min**3)**(1/3)

      Parameters
      ----------
      dist_inner : float [kpc]
          lower distance
      dist_outer : float [kpc]
          upper distance
      n_stars : int, None, optional
          number of stars drawn
          if None return one position as float

      Returns
      -------

      x : float, ndarray [kpc]
          Cartesian X coordinate (centered at the galactic center) of the drawn positions
      y : float, ndarray [kpc]
          Cartesian Y coordinate (centered at the galactic center) of the drawn positions
      z : float, ndarray [kpc]
          Cartesian Z coordinate (centered at the galactic center) of the drawn positions

      d_kpc : float, ndarray [kpc]
          distances of the drawn positions
      star_l_deg : float, ndarray [deg]
          galactic longitude of the drawn positions
      star_b_deg : float, ndarray [deg]
          galactic latitude of the drawn positions



   .. py:method:: rotate_00_to_lb(delta_l: numpy.ndarray, delta_b: numpy.ndarray) -> Tuple[numpy.ndarray, numpy.ndarray]

      Rotates coordinate system such that 0, 0 lands on self.l ,self.b

      Parameters
      ----------
      delta_l : float, ndarray [radians]
          difference in galactic longitude
      delta_b : float, ndarray [radians]
          difference in galactic longitude

      Returns
      -------
      star_l_rad : float, ndarray [radians]
          galactic longitude
      star_b_rad : float, ndarray [radians]
          galactic latitude