# autogalaxy.profiles.light.standard.Gaussian#

class Gaussian[source]#

Bases: LightProfile

The elliptical Gaussian light profile.

The intensity distribution of the profile is given by:

$I(\xi) = I \exp (-0.5 \xi / (\sigma / q^{0.5}))^2$

Where xi are elliptical coordinates calculated according to :class: SphProfile.

Parameters

Methods

 angle_to_profile_grid_from The angle between each angle theta on the grid and the profile, in radians. blurred_image_2d_from Evaluate the light object's 2D image from a input 2D grid of coordinates and convolve it with a PSF. dict A dictionary representation of the instance comprising a type field which contains the entire class path by which the type can be imported and constructor arguments. eccentric_radii_grid_from Convert a grid of (y,x) coordinates to an eccentric radius: :math: axis_ratio^0.5 (x^2 + (y^2/q))^0.5 elliptical_radii_grid_from Convert a grid of (y,x) coordinates to their elliptical radii values: :math: (x^2 + (y^2/q))^0.5 from_dict Instantiate an instance of a class from its dictionary representation. from_json Load the dictable object to a .json file, whereby all attributes are converted from the .json file's dictionary representation to create the instance of the object has Does this instance have an attribute which is of type cls? image_1d_from Returns the light profile's 1D image from a grid of Cartesian coordinates, which may have been transformed using the light profile's geometry. image_2d_from Returns the Gaussian light profile's 2D image from a 2D grid of Cartesian (y,x) coordinates. image_2d_via_radii_from 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. luminosity_integral Routine to integrate the luminosity of an elliptical light profile. luminosity_within_circle_from Integrate the light profile to compute the total luminosity within a circle of specified radius. output_to_json Output the dictable object to a .json file, whereby all attributes are converted to a dictionary representation first. padded_image_2d_from Evaluate the light object's 2D image from a input 2D grid of padded coordinates, where this padding is sufficient to encapsulate all surrounding pixels that will blur light into the original image given the 2D shape of the PSF's kernel. radial_grid_from Convert a grid of (y, x) coordinates, to their radial distances from the profile centre (e.g. rotated_grid_from_reference_frame_from Rotate a grid of (y,x) coordinates which have been transformed to the elliptical reference frame of a profile back to the original unrotated coordinate grid reference frame. transformed_from_reference_frame_grid_from Transform a grid of (y,x) coordinates from the reference frame of the profile to the original observer reference frame. transformed_to_reference_frame_grid_from Transform a grid of (y,x) coordinates to the reference frame of the profile. unmasked_blurred_image_2d_from Evaluate the light object's 2D image from a input 2D grid of coordinates and convolve it with a PSF, using a grid which is not masked. visibilities_from Evaluate the light object's 2D image from a input 2D grid of coordinates and transform this to an array of visibilities using a autoarray.operators.transformer.Transformer object and therefore a Fourier Transform.

Attributes

 angle The position angle in degrees of the major-axis of the ellipse defined by profile, defined counter clockwise from the positive x-axis (0.0 > angle > 180.0). angle_radians The position angle in radians of the major-axis of the ellipse defined by profile, defined counter clockwise from the positive x-axis (0.0 > angle > 2pi). axis_ratio The ratio of the minor-axis to major-axis (b/a) of the ellipse defined by profile (0.0 > q > 1.0). half_light_radius rtype float

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 (ndarray) – The radial distances from the centre of the profile, for each coordinate on the grid.

Return type

ndarray

image_2d_from(grid, operated_only=None)[source]#

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 (Union[ndarray, Grid2D, Grid2DIterate, Grid2DIrregular]) – The 2D (y, x) coordinates in the original reference frame of the grid.

Returns

The image of the Gaussian evaluated at every (y,x) coordinate on the transformed grid.

Return type

image