Source code for autogalaxy.profiles.light.standard.gaussian

import numpy as np
from typing import Optional, Tuple

import autoarray as aa

from autogalaxy.profiles.light.abstract import LightProfile
from autogalaxy.profiles.light.decorators import (
    check_operated_only,
)


[docs]class Gaussian(LightProfile): def __init__( self, centre: Tuple[float, float] = (0.0, 0.0), ell_comps: Tuple[float, float] = (0.0, 0.0), intensity: float = 0.1, sigma: float = 1.0, ): """ The elliptical Gaussian light profile. The intensity distribution of the profile is given by: .. math:: I(\\xi) = I \exp (-0.5 \\xi / (\sigma / q^{0.5}))^2 Where \\xi are elliptical coordinates calculated according to :class: SphProfile. Parameters ---------- centre The (y,x) arc-second coordinates of the profile centre. ell_comps The first and second ellipticity components of the elliptical coordinate system. intensity Overall intensity normalisation of the light profile (units are dimensionless and derived from the data the light profile's image is compared too, which is expected to be electrons per second). sigma The sigma value of the Gaussian, corresponding to ~ 1 / sqrt(2 log(2)) the full width half maximum. """ super().__init__(centre=centre, ell_comps=ell_comps, intensity=intensity) self.sigma = sigma
[docs] def image_2d_via_radii_from(self, grid_radii: np.ndarray) -> np.ndarray: """ Returns the 2D image of the Gaussian light profile from a grid of coordinates which are the radial distance of each coordinate from the its `centre`. Note: sigma is divided by sqrt(q) here. Parameters ---------- grid_radii The radial distances from the centre of the profile, for each coordinate on the grid. """ return np.multiply( self._intensity, np.exp( -0.5 * np.square( np.divide(grid_radii, self.sigma / np.sqrt(self.axis_ratio)) ) ), )
[docs] @aa.grid_dec.grid_2d_to_structure @check_operated_only @aa.grid_dec.transform @aa.grid_dec.relocate_to_radial_minimum def image_2d_from( self, grid: aa.type.Grid2DLike, operated_only: Optional[bool] = None ) -> np.ndarray: """ Returns the Gaussian light profile's 2D image from a 2D grid of Cartesian (y,x) coordinates. If the coordinates have not been transformed to the profile's geometry (e.g. translated to the profile `centre`), this is performed automatically. Parameters ---------- grid The 2D (y, x) coordinates in the original reference frame of the grid. Returns ------- image The image of the Gaussian evaluated at every (y,x) coordinate on the transformed grid. """ return self.image_2d_via_radii_from(self.eccentric_radii_grid_from(grid))
[docs]class GaussianSph(Gaussian): def __init__( self, centre: Tuple[float, float] = (0.0, 0.0), intensity: float = 0.1, sigma: float = 1.0, ): """ The spherical Gaussian light profile. Parameters ---------- centre The (y,x) arc-second coordinates of the profile centre. intensity Overall intensity normalisation of the light profile (units are dimensionless and derived from the data the light profile's image is compared too, which is expected to be electrons per second). sigma The sigma value of the Gaussian, corresponding to ~ 1 / sqrt(2 log(2)) the full width half maximum. """ super().__init__( centre=centre, ell_comps=(0.0, 0.0), intensity=intensity, sigma=sigma )