lsst.skymap  14.0-3-g20413be+2
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 from lsst.afw.coord import IcrsCoord
27 import lsst.afw.geom as afwGeom
28 from .cachingSkyMap import CachingSkyMap
29 from .tractInfo import ExplicitTractInfo
30 
31 __all__ = ["DiscreteSkyMap"]
32 
33 
34 class DiscreteSkyMapConfig(CachingSkyMap.ConfigClass):
35  """Configuration for the DiscreteSkyMap"""
36  raList = ListField(dtype=float, default=[], doc="Right Ascensions of tracts (ICRS, degrees)")
37  decList = ListField(dtype=float, default=[], doc="Declinations of tracts (ICRS, degrees)")
38  radiusList = ListField(dtype=float, default=[], doc="Radii of tracts (degrees)")
39 
40  def validate(self):
41  super(DiscreteSkyMapConfig, self).validate()
42  if len(self.radiusList) != len(self.raList):
43  raise ValueError("Number of radii (%d) and RAs (%d) do not match" %
44  (len(self.radiusList), len(self.raList)))
45  if len(self.radiusList) != len(self.decList):
46  raise ValueError("Number of radii (%d) and Decs (%d) do not match" %
47  (len(self.radiusList), len(self.decList)))
48 
49 
51  """Discrete sky map pixelization.
52 
53  We put a square Tract at each of the nominated coordinates.
54  """
55  ConfigClass = DiscreteSkyMapConfig
56  _version = (1, 0) # for pickle
57 
58  def __init__(self, config, version=0):
59  """Constructor
60 
61  @param[in] config: an instance of self.ConfigClass; if None the default config is used
62  @param[in] version: software version of this class, to retain compatibility with old instances
63  """
64  numTracts = len(config.radiusList)
65  super(DiscreteSkyMap, self).__init__(numTracts, config, version)
66 
67  def generateTract(self, index):
68  """Generate the TractInfo for a particular index"""
69  center = IcrsCoord(self.config.raList[index] * afwGeom.degrees,
70  self.config.decList[index] * afwGeom.degrees)
71  radius = self.config.radiusList[index]
72  wcs = self._wcsFactory.makeWcs(crPixPos=afwGeom.Point2D(0, 0), crValCoord=center)
73  return ExplicitTractInfo(index, self.config.patchInnerDimensions, self.config.patchBorder, center,
74  radius * afwGeom.degrees, self.config.tractOverlap * afwGeom.degrees, wcs)
75 
76  def updateSha1(self, sha1):
77  """Add subclass-specific state or configuration options to the SHA1."""
78  fmt = "<{}d".format(len(self.config.radiusList))
79  sha1.update(struct.pack(fmt, *self.config.raList))
80  sha1.update(struct.pack(fmt, *self.config.decList))
81  sha1.update(struct.pack(fmt, *self.config.radiusList))
def __init__(self, config, version=0)