lsst.skymap  15.0-8-g13fca11+11
discreteSkyMap.py
Go to the documentation of this file.
1 #
2 # LSST Data Management System
3 # Copyright 2008, 2009, 2010, 2012 LSST Corporation.
4 #
5 # This product includes software developed by the
6 # LSST Project (http://www.lsst.org/).
7 #
8 # This program is free software: you can redistribute it and/or modify
9 # it under the terms of the GNU General Public License as published by
10 # the Free Software Foundation, either version 3 of the License, or
11 # (at your option) any later version.
12 #
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
17 #
18 # You should have received a copy of the LSST License Statement and
19 # the GNU General Public License along with this program. If not,
20 # see <http://www.lsstcorp.org/LegalNotices/>.
21 #
22 
23 import struct
24 
25 from lsst.pex.config import ListField
26 import lsst.afw.geom as afwGeom
27 from .cachingSkyMap import CachingSkyMap
28 from .tractInfo import ExplicitTractInfo
29 
30 __all__ = ["DiscreteSkyMap"]
31 
32 
33 class DiscreteSkyMapConfig(CachingSkyMap.ConfigClass):
34  """Configuration for the DiscreteSkyMap"""
35  raList = ListField(dtype=float, default=[], doc="Right Ascensions of tracts (ICRS, degrees)")
36  decList = ListField(dtype=float, default=[], doc="Declinations of tracts (ICRS, degrees)")
37  radiusList = ListField(dtype=float, default=[], doc="Radii of tracts (degrees)")
38 
39  def validate(self):
40  super(DiscreteSkyMapConfig, self).validate()
41  if len(self.radiusList) != len(self.raList):
42  raise ValueError("Number of radii (%d) and RAs (%d) do not match" %
43  (len(self.radiusList), len(self.raList)))
44  if len(self.radiusList) != len(self.decList):
45  raise ValueError("Number of radii (%d) and Decs (%d) do not match" %
46  (len(self.radiusList), len(self.decList)))
47 
48 
50  """Discrete sky map pixelization.
51 
52  We put a square Tract at each of the nominated coordinates.
53  """
54  ConfigClass = DiscreteSkyMapConfig
55  _version = (1, 0) # for pickle
56 
57  def __init__(self, config, version=0):
58  """Constructor
59 
60  @param[in] config: an instance of self.ConfigClass; if None the default config is used
61  @param[in] version: software version of this class, to retain compatibility with old instances
62  """
63  numTracts = len(config.radiusList)
64  super(DiscreteSkyMap, self).__init__(numTracts, config, version)
65 
66  def generateTract(self, index):
67  """Generate the TractInfo for a particular index"""
68  center = afwGeom.SpherePoint(self.config.raList[index], self.config.decList[index], afwGeom.degrees)
69  radius = self.config.radiusList[index]
70  wcs = self._wcsFactory.makeWcs(crPixPos=afwGeom.Point2D(0, 0), crValCoord=center)
71  return ExplicitTractInfo(index, self.config.patchInnerDimensions, self.config.patchBorder, center,
72  radius * afwGeom.degrees, self.config.tractOverlap * afwGeom.degrees, wcs)
73 
74  def updateSha1(self, sha1):
75  """Add subclass-specific state or configuration options to the SHA1."""
76  fmt = "<{}d".format(len(self.config.radiusList))
77  sha1.update(struct.pack(fmt, *self.config.raList))
78  sha1.update(struct.pack(fmt, *self.config.decList))
79  sha1.update(struct.pack(fmt, *self.config.radiusList))
def __init__(self, config, version=0)