lsst.meas.algorithms  22.0.1-23-gc2439a9a+e37b83d4fa
htmIndexer.py
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23 
24 __all__ = ["HtmIndexer"]
25 
26 import esutil
27 
28 
29 class HtmIndexer:
30  """Manage a spatial index of hierarchical triangular mesh (HTM)
31  shards.
32 
33  Parameters
34  ----------
35  depth : `int`
36  Depth of the HTM hierarchy to construct.
37  """
38  def __init__(self, depth=7):
39  self.htmhtm = esutil.htm.HTM(depth)
40 
41  def getShardIds(self, ctrCoord, radius):
42  """Get the IDs of all shards that touch a circular aperture.
43 
44  Parameters
45  ----------
46  ctrCoord : `lsst.geom.SpherePoint`
47  ICRS center of search region.
48  radius : `lsst.geom.Angle`
49  Radius of search region.
50 
51  Returns
52  -------
53  results : `tuple`
54  A tuple containing:
55 
56  - shardIdList : `list` of `int`
57  List of shard IDs
58  - isOnBoundary : `list` of `bool`
59  For each shard in ``shardIdList`` is the shard on the
60  boundary (not fully enclosed by the search region)?
61  """
62  shardIdList = self.htmhtm.intersect(ctrCoord.getLongitude().asDegrees(),
63  ctrCoord.getLatitude().asDegrees(),
64  radius.asDegrees(), inclusive=True)
65  coveredShardIdList = self.htmhtm.intersect(ctrCoord.getLongitude().asDegrees(),
66  ctrCoord.getLatitude().asDegrees(),
67  radius.asDegrees(), inclusive=False)
68  isOnBoundary = (shardId not in coveredShardIdList for shardId in shardIdList)
69  return shardIdList, isOnBoundary
70 
71  def indexPoints(self, raList, decList):
72  """Generate shard IDs for sky positions.
73 
74  Parameters
75  ----------
76  raList : `list` of `float`
77  List of right ascensions, in degrees.
78  decList : `list` of `float`
79  List of declinations, in degrees.
80 
81  Returns
82  -------
83  shardIds : `list` of `int`
84  List of shard IDs
85  """
86  return self.htmhtm.lookup_id(raList, decList)
87 
88  @staticmethod
89  def makeDataId(shardId, datasetName):
90  """Make a data id from a shard ID.
91 
92  Parameters
93  ----------
94  shardId : `int`
95  ID of shard in question.
96  datasetName : `str`
97  Name of dataset to use.
98 
99  Returns
100  -------
101  dataId : `dict`
102  Data ID for shard.
103  """
104  if shardId is None:
105  # NoneType doesn't format, so make dummy pixel
106  shardId = 0
107  return {'pixel_id': shardId, 'name': datasetName}
def getShardIds(self, ctrCoord, radius)
Definition: htmIndexer.py:41
def indexPoints(self, raList, decList)
Definition: htmIndexer.py:71
def makeDataId(shardId, datasetName)
Definition: htmIndexer.py:89