24 - Consider tweaking pixel scale so the average scale is as specified, rather than the scale at the center 33 __all__ = [
"BaseSkyMap"]
37 patchInnerDimensions = pexConfig.ListField(
38 doc=
"dimensions of inner region of patches (x,y pixels)",
43 patchBorder = pexConfig.Field(
44 doc=
"border between patch inner and outer bbox (pixels)",
48 tractOverlap = pexConfig.Field(
49 doc=
"minimum overlap between adjacent sky tracts, on the sky (deg)",
53 pixelScale = pexConfig.Field(
54 doc=
"nominal pixel scale (arcsec/pixel)",
58 projection = pexConfig.Field(
59 doc=
"""one of the FITS WCS projection codes, such as: 60 - STG: stereographic projection 61 - MOL: Molleweide's projection 62 - TAN: tangent-plane projection 67 rotation = pexConfig.Field(
68 doc=
"Rotation for WCS (deg)",
75 """A collection of overlapping Tracts that map part or all of the sky. 77 See TractInfo for more information. 79 BaseSkyMap is an abstract base class. Subclasses must do the following: 80 @li define __init__ and have it construct the TractInfo objects and put them in _tractInfoList 81 @li define __getstate__ and __setstate__ to allow pickling (the butler saves sky maps using pickle); 82 see DodecaSkyMap for an example of how to do this. (Most of that code could be moved 83 into this base class, but that would make it harder to handle older versions of pickle data.) 84 @li define updateSha1 to add any subclass-specific state to the hash. 86 All SkyMap subclasses must be conceptually immutable; they must always 87 refer to the same set of mathematical tracts and patches even if the in- 88 memory representation of those objects changes. 90 ConfigClass = BaseSkyMapConfig
93 """Construct a BaseSkyMap 95 @param[in] config: an instance of self.ConfigClass; if None the default config is used 103 pixelScale=afwGeom.Angle(self.
config.pixelScale, afwGeom.arcseconds),
104 projection=self.
config.projection,
105 rotation=afwGeom.Angle(self.
config.rotation, afwGeom.degrees),
110 """Find the tract whose center is nearest the specified coord. 112 @param[in] coord: ICRS sky coordinate (lsst.afw.geom.SpherePoint) 113 @return TractInfo of tract whose center is nearest the specified coord 116 - if tracts do not cover the whole sky then the returned tract may not include the coord 119 - This routine will be more efficient if coord is ICRS. 120 - If coord is equidistant between multiple sky tract centers then one is arbitrarily chosen. 121 - The default implementation is not very efficient; subclasses may wish to override. 123 distTractInfoList = []
124 for tractInfo
in self:
125 angSep = coord.separation(tractInfo.getCtrCoord()).asDegrees()
126 distTractInfoList.append((angSep, tractInfo))
127 distTractInfoList.sort()
128 return distTractInfoList[0][1]
131 """Find tracts and patches that overlap a region 133 @param[in] coordList: list of ICRS sky coordinates (lsst.afw.geom.SpherePoint) 134 @return list of (TractInfo, list of PatchInfo) for tracts and patches that contain, 135 or may contain, the specified region. The list will be empty if there is no overlap. 137 @warning this uses a naive algorithm that may find some tracts and patches that do not overlap 138 the region (especially if the region is not a rectangle aligned along patch x,y). 141 for tractInfo
in self:
142 patchList = tractInfo.findPatchList(coordList)
144 retList.append((tractInfo, patchList))
148 """Find closest tract and patches that overlap coordinates 150 @param[in] coordList: list of ICRS sky coordinates (lsst.afw.geom.SpherePoint) 151 @return list of (TractInfo, list of PatchInfo) for tracts and patches that contain, 152 or may contain, the specified region. The list will be empty if there is no overlap. 155 for coord
in coordList:
157 patchList = tractInfo.findPatchList(coordList)
158 if patchList
and not (tractInfo, patchList)
in retList:
159 retList.append((tractInfo, patchList))
176 return self.
getSha1() == other.getSha1()
177 except AttributeError:
178 return NotImplemented
181 return not (self == other)
184 """Return a SHA1 hash that uniquely identifies this SkyMap instance. 189 A 20-byte hash that uniquely identifies this SkyMap instance. 191 Subclasses should almost always override `updateSha1()` instead of 192 this function to add subclass-specific state to the hash. 194 if self.
_sha1 is None:
195 sha1 = hashlib.sha1()
196 sha1.update(type(self).__name__.encode(
'utf-8'))
197 configPacked = struct.pack(
199 self.
config.patchInnerDimensions[0],
200 self.
config.patchInnerDimensions[1],
204 self.
config.projection.encode(
'ascii'),
207 sha1.update(configPacked)
209 self.
_sha1 = sha1.digest()
213 """Add subclass-specific state or configuration options to the SHA1. 218 A hashlib object on which `update()` can be called to add 219 additional state to the hash. 221 This method is conceptually "protected": it should be reimplemented by 222 all subclasses, but called only by the base class implementation of 225 raise NotImplementedError()
def updateSha1(self, sha1)
def findTractPatchList(self, coordList)
def findClosestTractPatchList(self, coordList)
def __getitem__(self, ind)
def findTract(self, coord)
def __init__(self, config=None)