RandomSDSS

Generate random points within SDSS DR8 to DR16 footprint.

exception randomsdss.PolygonNotFoundError[source]

Bases: FileNotFoundError

Raised when the .ply file doesn’t exists.

class randomsdss.DR(dr, catalog)[source]

Bases: object

Base Data Release class.

Parameters

  • dr (str) – Data Release name: e.g DR16.

  • catalog (str) – Catalog name within the specified data release: e.g. BOSS.

box_random(ra_min, ra_max, dec_min, dec_max, size)[source]

Generate random RA, DEC points within a box.

Parameters

  • ra_min (float) – Right Ascension lower bound in degrees.

  • ra_max (float) – Right Ascension upper bound in degrees.

  • dec_min (float) – Declination lower bound in degrees.

  • dec_max (float) – Declination upper bound in degrees.

  • size (int) – Number of random points to generate.

Returns

  • ra (numpy.ndarray) – Right Ascension in degrees.

  • dec (numpy.ndarray) – Declination in degrees.

contains(ra, dec)[source]

Check if point is inside the catalog area.

Parameters

  • ra (numpy.ndarray) – Right Ascension in degrees.

  • dec (numpy.ndarray) – Declination in degrees.

Returns

True if inside, False otherwise.

Return type

bool

polyid(ra, dec)[source]

Get polygon id of input point.

Parameters

  • ra (numpy.ndarray) – Right Ascension in degrees.

  • dec (numpy.ndarray) – Declination in degrees.

Returns

pid – Polygon id. -1 if outside of catalog area.

Return type

numpy.ndarray

polyid_and_weight(ra, dec)[source]

Get polygon id and weight of input point.

Parameters

  • ra (numpy.ndarray) – Right Ascension in degrees.

  • dec (numpy.ndarray) – Declination in degrees.

Returns

  • pid (numpy.ndarray) – Polygon id. -1 if outside of catalog area.

  • weight (numpy.ndarray) – Poligon weight. 0 if outside of catalog area.

set_weights(weights)[source]

Set new weights for polygons.

Parameters

weight (float or numpy.ndarray) – Poligons weights.

sky_random(size)[source]

Generate random RA, DEC points.

Parameters

size (int) – Number of random points to generate.

Returns

  • ra (numpy.ndarray) – Right Ascension in degrees.

  • dec (numpy.ndarray) – Declination in degrees.

weight(ra, dec)[source]

Get polygon weight of input point.

Parameters

  • ra (numpy.ndarray) – Right Ascension in degrees.

  • dec (numpy.ndarray) – Declination in degrees.

Returns

weight – Poligon weight. 0 if outside of catalog area.

Return type

numpy.ndarray

property area

Get the area of the catalog.

property npoly

Get the number of polygons.

property weights

Array of polygons weights.

class randomsdss.DR10(catalog='SDSS')

Bases: randomsdss.randomsdss.DR

class randomsdss.DR11(catalog='SDSS')

Bases: randomsdss.randomsdss.DR

class randomsdss.DR12(catalog='SDSS')

Bases: randomsdss.randomsdss.DR

class randomsdss.DR13(catalog='SDSS')

Bases: randomsdss.randomsdss.DR

class randomsdss.DR14(catalog='SDSS')

Bases: randomsdss.randomsdss.DR

class randomsdss.DR15(catalog='SDSS')

Bases: randomsdss.randomsdss.DR

class randomsdss.DR16(catalog='SDSS')

Bases: randomsdss.randomsdss.DR

class randomsdss.DR8(catalog='SDSS')

Bases: randomsdss.randomsdss.DR

class randomsdss.DR9(catalog='SDSS')

Bases: randomsdss.randomsdss.DR

randomsdss.sky_random(dr='DR16', catalog='SDSS', size=10000)[source]

Generate random RA, DEC values within the specified DR and catalog.

Parameters

  • dr (str) – Data Release name: e.g DR16.

  • catalog (str) – Catalog name within the specified data release: e.g. BOSS.

  • size (int) – Number of random points to generate.

Returns

  • ra (numpy.ndarray) – Right Ascension in degrees.

  • dec (numpy.ndarray) – Declination in degrees.

randomsdss.z_random(z, size=10000, weights=None, seed=None)[source]

Generate random redshift values following the input distribution.

This function uses scipy.stats.gaussian_kde to compute the Probability Density Distribution (PDF).

Parameters

  • z (numpy.ndarray) – Redhisft sample to generate a PDF and extract random points.

  • size (int) – Number of random points to generate.

  • weights (numpy.ndarray) – Weigths of each redshift value to compute a weigthed PDF.

  • seed (int) – Set random seed.

Returns

z_rand – Random redshifts.

Return type

numpy.ndarray