Point-Source Analysis

basis.py

author

Ruyman Azzollini

Created on Thu Apr 20 18:56:40 2017

class vison.point.basis.SpotBase(data, log=None, verbose=False)

display.py

Display Library for Point-Source Analysis

Created on Fri Apr 21 14:02:57 2017

requires

matplotlib

author

Ruyman Azzollini

vison.point.display.show_spots_allCCDs(spots_bag, title='', filename='', dobar=True)

gauss.py

Gaussian Model of Point-like Sources

Simple class to do Gaussian Fitting to a spot.

requires

NumPy, astropy

Created on Thu Apr 20 16:42:47 2017

author

Ruyman Azzollini

class vison.point.gauss.Gaussmeter(data, log=None, verbose=False, **kwargs)

Provides methods to measure the shape of an object using a 2D Gaussian Model.

Parameters

  • data (np.ndarray) – stamp to be analysed.

  • log (instance) – logger

  • kwargs (dict) – additional keyword arguments

Settings dictionary contains all parameter values needed.

fit_Gauss(verbose=False)

models.py

Models (Point-Like Sources)

Library module with models for processing of point-source imaging data.

requires

NumPy

author

Ruyman Azzollini

Created on Wed Apr 19 11:47:00 2017

vison.point.models.fgauss2D(x, y, p)
A gaussian fitting function where

p[0] = amplitude p[1] = x0 p[2] = y0 p[3] = sigmax p[4] = sigmay p[5] = floor

photom.py

Aperture Photometry of point-like objects

Simple class to do aperture photometry on a stamp of a point-source.

requires

NumPy

Created on Thu Apr 20 14:37:46 2017

author

Ruyman Azzollini

class vison.point.photom.Photometer(data, log=None, verbose=False, **kwargs)

Provides methods to measure the shape of an object.

Parameters

  • data (np.ndarray) – stamp to be analysed.

  • log (instance) – logger

  • kwargs (dict) – additional keyword arguments

Settings dictionary contains all parameter values needed.

doap_photom(centre, rap, rin=- 1.0, rout=- 1.0, gain=3.5, doErrors=True, subbgd=False)
get_centroid(rap=None, full=False)
TODO:

add aperture masking

measure_bgd(rin, rout)
sub_bgd(rin, rout)

shape.py

Quadrupole Moments Shape Measurement

Simple class to measure quadrupole moments and ellipticity of an object.

requires

NumPy, PyFITS

author

Sami-Matias Niemi, Ruyman Azzollini

class vison.point.shape.Shapemeter(data, log=None, verbose=False, **kwargs)

Provides methods to measure the shape of an object.

Parameters

  • data (np.ndarray) – stamp to be analysed.

  • log (instance) – logger

  • kwargs (dict) – additional keyword arguments

Settings dictionary contains all parameter values needed.

circular2DGaussian(x, y, sigma)

Create a circular symmetric Gaussian centered on x, y.

Parameters

  • x (float) – x coordinate of the centre

  • y (float) – y coordinate of the centre

  • sigma (float) – standard deviation of the Gaussian, note that sigma_x = sigma_y = sigma

Returns

circular Gaussian 2D profile and x and y mesh grid

Return type

dict

ellip2DGaussian(x, y, sigmax, sigmay)

Create a two-dimensional Gaussian centered on x, y.

Parameters

  • x (float) – x coordinate of the centre

  • y (float) – y coordinate of the centre

  • sigmax (float) – standard deviation of the Gaussian in x-direction

  • sigmay (float) – standard deviation of the Gaussian in y-direction

Returns

circular Gaussian 2D profile and x and y mesh grid

Return type

dict

measureRefinedEllipticity()

Derive a refined iterated polarisability/ellipticity measurement for a given object.

By default polarisability/ellipticity is defined in terms of the Gaussian weighted quadrupole moments. If self.shsettings[‘weighted’] is False then no weighting scheme is used.

The number of iterations is defined in self.shsettings[‘iterations’].

Returns

centroids [indexing stars from 1], ellipticity (including projected e1 and e2), and R2

Return type

dict

quadrupoles(image)

Derive quadrupole moments and ellipticity from the input image.

Parameters

img (ndarray) – input image data

Returns

quadrupoles, centroid, and ellipticity (also the projected components e1, e2)

Return type

dict

writeFITS(data, output)

Write out a FITS file using PyFITS.

Parameters

  • data (ndarray) – data to write to a FITS file

  • output (string) – name of the output file

Returns

None

spot.py

Spot Stamp Class.

Created on Thu Apr 20 15:35:08 2017

author

Ruyman Azzollini

class vison.point.spot.Spot(data, log=None, verbose=False, lowerleft=None, **kwargs)

Provides methods to do point-source analysis on a stamp. Aimed at basic analysis:

  • Photometry

  • Quadrupole Moments

  • Gaussian Fit

Parameters

  • data (np.ndarray) – stamp to be analysed.

  • log (instance) – logger

  • kwargs (dict) – additional keyword arguments

Settings dictionary contains all parameter values needed.

get_photom()

measurements:’apflu’,’eapflu’,’bgd’,’ebgd’

get_shape_Gauss()
Returns

res = dict(i0,ei0,x,ex,y,ey, sigma_x,esigma_x,sigmay,esigma_y, fwhm_x,efwhm_x, fwhm_y,efwhm_y, fluence,efluence)

get_shape_Moments()
Returns

res = dict(x,y,ellip,e1,e2,a,b)

get_shape_easy(method='G', debug=False)
measure_basic(rap=10, rin=15, rout=- 1, gain=3.1, debug=False)

# TODO: # get basic statistics, measure and subtract background # update centroid # do aperture photometry # pack-up results and return

Parameters

  • rap – source extraction aperture radius.

  • rin – inner radius of background annulus.

  • rout – outer radius of background annulus (-1 to set bound by image area).

  • gain – image gain (e-/ADU).

lib.py

Library module with useful data and functions for processing of point-source imaging data.

Created on Wed Apr 5 10:21:05 2017

author

Ruyman Azzollini (except where indicated)

vison.point.lib.extract_spot(ccdobj, coo, Quad, log=None, stampw=25)
vison.point.lib.gen_point_mask(Quad, width=75, sources='all', coodict={'CCD1': {'E': {'ALPHA': 460.6, 3754.8, 'BRAVO': 1689.4, 3754.8, 'CHARLIE': 1075.0, 3129.0, 'DELTA': 460.6, 2503.2, 'ECHO': 1689.4, 2503.2}, 'F': {'ALPHA': 2579.6, 3754.8, 'BRAVO': 3808.4, 3754.8, 'CHARLIE': 3194.0, 3129.0, 'DELTA': 2579.6, 2503.2, 'ECHO': 3808.4, 2503.2}, 'G': {'ALPHA': 2579.6, 1668.8000000000002, 'BRAVO': 3808.4, 1668.8000000000002, 'CHARLIE': 3194.0, 1043.0, 'DELTA': 2579.6, 417.20000000000005, 'ECHO': 3808.4, 417.20000000000005}, 'H': {'ALPHA': 460.6, 1668.8000000000002, 'BRAVO': 1689.4, 1668.8000000000002, 'CHARLIE': 1075.0, 1043.0, 'DELTA': 460.6, 417.20000000000005, 'ECHO': 1689.4, 417.20000000000005}}, 'CCD2': {'E': {'ALPHA': 542.0, 1725.0, 'BRAVO': 1716.0, 1700.0, 'CHARLIE': 1126.0, 1124.0, 'DELTA': 521.0, 551.0, 'ECHO': 1695.0, 537.0}, 'F': {'ALPHA': 578.0, 1686.0, 'BRAVO': 1745.0, 1668.0, 'CHARLIE': 1141.0, 1144.0, 'DELTA': 553.0, 522.0, 'ECHO': 1723.0, 496.0}, 'G': {'ALPHA': 534.0, 1590.0, 'BRAVO': 1702.0, 1571.0, 'CHARLIE': 1139.0, 1033.0, 'DELTA': 515.0, 415.0, 'ECHO': 1685.0, 394.0}, 'H': {'ALPHA': 554.0, 1626.0, 'BRAVO': 1725.0, 1606.0, 'CHARLIE': 1131.0, 1029.0, 'DELTA': 531.0, 446.0, 'ECHO': 1706.0, 435.0}}, 'CCD3': {'E': {'ALPHA': 460.6, 3754.8, 'BRAVO': 1689.4, 3754.8, 'CHARLIE': 1075.0, 3129.0, 'DELTA': 460.6, 2503.2, 'ECHO': 1689.4, 2503.2}, 'F': {'ALPHA': 2579.6, 3754.8, 'BRAVO': 3808.4, 3754.8, 'CHARLIE': 3194.0, 3129.0, 'DELTA': 2579.6, 2503.2, 'ECHO': 3808.4, 2503.2}, 'G': {'ALPHA': 2579.6, 1668.8000000000002, 'BRAVO': 3808.4, 1668.8000000000002, 'CHARLIE': 3194.0, 1043.0, 'DELTA': 2579.6, 417.20000000000005, 'ECHO': 3808.4, 417.20000000000005}, 'H': {'ALPHA': 460.6, 1668.8000000000002, 'BRAVO': 1689.4, 1668.8000000000002, 'CHARLIE': 1075.0, 1043.0, 'DELTA': 460.6, 417.20000000000005, 'ECHO': 1689.4, 417.20000000000005}}, 'names': ['ALPHA', 'BRAVO', 'CHARLIE', 'DELTA', 'ECHO']})