lsst.skymap  16.0-4-g13a27c5+14
Public Member Functions | Public Attributes | Static Public Attributes | List of all members
lsst.skymap.ringsSkyMap.RingsSkyMap Class Reference
Inheritance diagram for lsst.skymap.ringsSkyMap.RingsSkyMap:
lsst.skymap.cachingSkyMap.CachingSkyMap lsst.skymap.baseSkyMap.BaseSkyMap

Public Member Functions

def __init__ (self, config, version=1)
 
def getRingIndices (self, index)
 
def generateTract (self, index)
 
def findTract (self, coord)
 
def findAllTracts (self, coord)
 
def findTractPatchList (self, coordList)
 
def updateSha1 (self, sha1)
 
def __reduce__ (self)
 
def __iter__ (self)
 
def __len__ (self)
 
def __getitem__ (self, index)
 
def findClosestTractPatchList (self, coordList)
 
def __hash__ (self)
 
def __eq__ (self, other)
 
def __ne__ (self, other)
 
def getSha1 (self)
 
def register (self, name, registry)
 

Public Attributes

 config
 

Static Public Attributes

 ConfigClass = RingsSkyMapConfig
 

Detailed Description

Rings sky map pixelization.

We divide the sphere into N rings of Declination, plus the two polar
caps, which sets the size of the individual tracts.  The rings are
divided in RA into an integral number of tracts of this size; this
division is made at the Declination closest to zero so as to ensure
full overlap.

Rings are numbered in the rings from south to north. The south pole cap is
``tract=0``, then the tract at ``raStart`` in the southernmost ring is
``tract=1``. Numbering continues (in the positive RA direction) around that
ring and then continues in the same fashion with the next ring north, and
so on until all reaching the north pole cap, which is
``tract=len(skymap) - 1``.

However, ``version=0`` had a bug in the numbering of the tracts: the first
and last tracts in the first (southernmost) ring were identical, and the
first tract in the last (northernmost) ring was missing. When using
``version=0``, these tracts remain missing in order to preserve the
numbering scheme.

Parameters
----------
config : `lsst.skymap.RingsSkyMapConfig`
    Configuration for this skymap.
version : `int`, optional
    Software version of this class, to retain compatibility with old
    verisons. ``version=0`` covers the period from first implementation
    until DM-14809, at which point bugs were identified in the numbering
    of tracts (affecting only tracts at RA=0). ``version=1`` uses the
    post-DM-14809 tract numbering.

Definition at line 41 of file ringsSkyMap.py.

Constructor & Destructor Documentation

◆ __init__()

def lsst.skymap.ringsSkyMap.RingsSkyMap.__init__ (   self,
  config,
  version = 1 
)
Constructor

Definition at line 77 of file ringsSkyMap.py.

Member Function Documentation

◆ __eq__()

def lsst.skymap.baseSkyMap.BaseSkyMap.__eq__ (   self,
  other 
)
inherited

Definition at line 175 of file baseSkyMap.py.

◆ __getitem__()

def lsst.skymap.cachingSkyMap.CachingSkyMap.__getitem__ (   self,
  index 
)
inherited
Get the TractInfo for a particular index

The tract is returned from a cache, if available, otherwise generated
on the fly.

Definition at line 66 of file cachingSkyMap.py.

◆ __hash__()

def lsst.skymap.baseSkyMap.BaseSkyMap.__hash__ (   self)
inherited

Definition at line 172 of file baseSkyMap.py.

◆ __iter__()

def lsst.skymap.cachingSkyMap.CachingSkyMap.__iter__ (   self)
inherited
Iterator over tracts

Definition at line 57 of file cachingSkyMap.py.

◆ __len__()

def lsst.skymap.cachingSkyMap.CachingSkyMap.__len__ (   self)
inherited
Length is number of tracts

Definition at line 62 of file cachingSkyMap.py.

◆ __ne__()

def lsst.skymap.baseSkyMap.BaseSkyMap.__ne__ (   self,
  other 
)
inherited

Definition at line 181 of file baseSkyMap.py.

◆ __reduce__()

def lsst.skymap.cachingSkyMap.CachingSkyMap.__reduce__ (   self)
inherited
To support pickling

Warning: This method assumes that the constructor should be defined:
    __init__(self, config, version=defaultVersion)
The use of 'config' is effectively set by the registry mechanism.
If additional optional arguments are added, this method should be
overridden to correspond.

Definition at line 46 of file cachingSkyMap.py.

◆ findAllTracts()

def lsst.skymap.ringsSkyMap.RingsSkyMap.findAllTracts (   self,
  coord 
)
Find all tracts which include the specified coord.

@param[in] coord: sky coordinate (afwCoord.Coord)
@return List of TractInfo of tracts which include the specified coord

@note
- This routine will be more efficient if coord is ICRS.

Definition at line 216 of file ringsSkyMap.py.

◆ findClosestTractPatchList()

def lsst.skymap.baseSkyMap.BaseSkyMap.findClosestTractPatchList (   self,
  coordList 
)
inherited
Find closest tract and patches that overlap coordinates

@param[in] coordList: list of ICRS sky coordinates (lsst.afw.geom.SpherePoint)
@return list of (TractInfo, list of PatchInfo) for tracts and patches that contain,
    or may contain, the specified region. The list will be empty if there is no overlap.

Definition at line 148 of file baseSkyMap.py.

◆ findTract()

def lsst.skymap.ringsSkyMap.RingsSkyMap.findTract (   self,
  coord 
)
Find the tract whose center is nearest the specified coord.

@param[in] coord: sky coordinate (afwCoord.Coord)
@return TractInfo of tract whose center is nearest the specified coord

@warning:
- if tracts do not cover the whole sky then the returned tract may not include the coord

@note
- If coord is equidistant between multiple sky tract centers then one is arbitrarily chosen.

Definition at line 187 of file ringsSkyMap.py.

◆ findTractPatchList()

def lsst.skymap.ringsSkyMap.RingsSkyMap.findTractPatchList (   self,
  coordList 
)
Find tracts and patches that overlap a region

@param[in] coordList: list of sky coordinates (afwCoord.Coord)
@return list of (TractInfo, list of PatchInfo) for tracts and patches that contain,
    or may contain, the specified region. The list will be empty if there is no overlap.

@warning this uses a naive algorithm that may find some tracts and patches that do not overlap
    the region (especially if the region is not a rectangle aligned along patch x,y).

Definition at line 263 of file ringsSkyMap.py.

◆ generateTract()

def lsst.skymap.ringsSkyMap.RingsSkyMap.generateTract (   self,
  index 
)
Generate the TractInfo for this index

Definition at line 124 of file ringsSkyMap.py.

◆ getRingIndices()

def lsst.skymap.ringsSkyMap.RingsSkyMap.getRingIndices (   self,
  index 
)
Calculate ring indices given a numerical index of a tract

The ring indices are the ring number and the tract number within
the ring.

The ring number is -1 for the south polar cap and increases to the
north.  The north polar cap has ring number = numRings.  The tract
number is zero for either of the polar caps.

Definition at line 93 of file ringsSkyMap.py.

◆ getSha1()

def lsst.skymap.baseSkyMap.BaseSkyMap.getSha1 (   self)
inherited
Return a SHA1 hash that uniquely identifies this SkyMap instance.

Returns
-------
sha1 : bytes
    A 20-byte hash that uniquely identifies this SkyMap instance.

Subclasses should almost always override `updateSha1()` instead of
this function to add subclass-specific state to the hash.

Definition at line 184 of file baseSkyMap.py.

◆ register()

def lsst.skymap.baseSkyMap.BaseSkyMap.register (   self,
  name,
  registry 
)
inherited
Add SkyMap, Tract, and Patch DataUnits to the given Gen3 Butler Registry.

Definition at line 228 of file baseSkyMap.py.

◆ updateSha1()

def lsst.skymap.ringsSkyMap.RingsSkyMap.updateSha1 (   self,
  sha1 
)
Add subclass-specific state or configuration options to the SHA1.

Definition at line 281 of file ringsSkyMap.py.

Member Data Documentation

◆ config

lsst.skymap.baseSkyMap.BaseSkyMap.config
inherited

Definition at line 100 of file baseSkyMap.py.

◆ ConfigClass

lsst.skymap.ringsSkyMap.RingsSkyMap.ConfigClass = RingsSkyMapConfig
static

Definition at line 74 of file ringsSkyMap.py.


The documentation for this class was generated from the following file: