lsst.pipe.tasks g2e17d592ec+c990792287
Loading...
Searching...
No Matches
Functions
lsst.pipe.tasks.associationUtils Namespace Reference

Functions

 toIndex (nside, ra, dec)
 
 toRaDec (nside, index)
 
 eq2xyz (ra, dec)
 
 eq2xyzVec (ra, dec)
 
 convert_spherical (ra, dec)
 
 convert_spherical_array (array)
 
 query_disc (nside, ra, dec, max_rad, min_rad=0)
 

Detailed Description

Utilities for interfacing with hpgeom. Originally implemented in
http://github.com/LSSTDESC/dia_pipe and then translated to hpgeom.

Function Documentation

◆ convert_spherical()

lsst.pipe.tasks.associationUtils.convert_spherical ( ra,
dec )
Convert from ra,dec to spherical coordinates.

Used in query_disc.

Parameters
----------
ra : `float`
    RA in radians.
dec : `float`
    Declination in radians

Definition at line 124 of file associationUtils.py.

◆ convert_spherical_array()

lsst.pipe.tasks.associationUtils.convert_spherical_array ( array)
Convert from and a array ra,dec to spherical coordinates.

Used in query_disc

Parameters
----------
array : `numpy.ndarray`, (N, 2)
    (N, 2) Array of RA, DEC values.

Returns
-------
vecs : `numpy.ndarray`, (N, 3)
    Vectors on the unit sphere

Definition at line 141 of file associationUtils.py.

◆ eq2xyz()

lsst.pipe.tasks.associationUtils.eq2xyz ( ra,
dec )
Convert from equatorial ra,dec in degrees to x,y,z on unit sphere.

Parameters
----------
ra : `float`
    RA in degrees.
dec : `float`
    Declination in degrees

Returns
-------
xyz : `numpy.ndarray`, (3,)
    Float xyz positions on the unit sphere.

Definition at line 72 of file associationUtils.py.

◆ eq2xyzVec()

lsst.pipe.tasks.associationUtils.eq2xyzVec ( ra,
dec )
Convert equatorial ra,dec in degrees to x,y,z on the unit sphere
parameters

Vectorized version of ``eq2xyz``

Parameters
----------
ra : array_like, (N,)
    Array of RA in degrees.
dec : array_like, (N,)
    Declination in degrees

Returns
-------
vec : `numpy.ndarray`, (N,3)
    Array of unitsphere 3-vectors.

Definition at line 96 of file associationUtils.py.

◆ query_disc()

lsst.pipe.tasks.associationUtils.query_disc ( nside,
ra,
dec,
max_rad,
min_rad = 0 )
Get the list of healpix indices within max_rad, min_rad given in radians
around ra,dec given in degrees

Parameters
----------
nside : `int`
    Resolution of the healpixels to search/return.
ra : `float`
    RA in degrees.
dec : `float`
    Declination in degrees
max_rad : `float`
    Max distance in radians to search nearby healpixels.
min_rad : `float`, optional
    Minimum distance in radians to search healpixels. Default = 0.

Definition at line 161 of file associationUtils.py.

◆ toIndex()

lsst.pipe.tasks.associationUtils.toIndex ( nside,
ra,
dec )
Return healpix index given ra, dec in degrees

Parameters
----------
nside : `int`
    Power of 2 nside healpix resolution.
ra : `float`
    RA in degrees.
dec : `float`
    Declination in degrees

Returns
-------
index : `int`
    Unique healpix pixel ID containing point RA, DEC at resolution nside.

Definition at line 33 of file associationUtils.py.

◆ toRaDec()

lsst.pipe.tasks.associationUtils.toRaDec ( nside,
index )
Convert from healpix index to ra,dec in degrees

Parameters
----------
nside : `int`
    Resolution of healpixel "grid".
index : `int`
    Index of the healpix pixel we want to find the location of.

Returns
-------
pos : `numpy.ndarray`, (2,)
    RA and DEC of healpix pixel location in degrees.

Definition at line 53 of file associationUtils.py.