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# 

# LSST Data Management System 

# Copyright 2008, 2009, 2010 LSST Corporation. 

# 

# This product includes software developed by the 

# LSST Project (http://www.lsst.org/) . 

# 

# 

# This program is free software: you can redistribute it and/or modify 

# it under the terms of the GNU General Public License as published by 

# the Free Software Foundation, either version 3 of the License, or 

# (at your option) any later version. 

# 

# This program is distributed in the hope that it will be useful, 

# but WITHOUT ANY WARRANTY; without even the implied warranty of 

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 

# GNU General Public License for more details. 

# 

# You should have received a copy of the LSST License Statement and 

# the GNU General Public License along with this program. If not, 

# see <http://www.lsstcorp.org/LegalNotices/>. 

# 

 

"""Consider tweaking pixel scale so the average scale is as specified, rather 

than the scale at the center. 

""" 

 

__all__ = ['DodecaSkyMapConfig', 'DodecaSkyMap'] 

 

import struct 

 

import lsst.pex.config as pexConfig 

import lsst.geom as geom 

from . import detail 

from .baseSkyMap import BaseSkyMap 

from .tractInfo import TractInfo 

 

 

class DodecaSkyMapConfig(BaseSkyMap.ConfigClass): 

withTractsOnPoles = pexConfig.Field( 

doc="if True center a tract on each pole, else put a vertex on each pole", 

dtype=bool, 

default=False, 

) 

 

def setDefaults(self): 

self.tractOverlap = 3.5 

self.patchBorder = 250 

self.pixelScale = 10.0 / 50.0 # LSST plate scale is 50 um/arcsec and pixel size is 10 um 

self.patchInnerDimensions = (4000, 4000) 

self.projection = "STG" 

 

 

class DodecaSkyMap(BaseSkyMap): 

"""Dodecahedron-based sky map pixelization. 

 

DodecaSkyMap divides the sky into 12 overlapping Tracts arranged as the 

faces of a dodecahedron. 

 

Parameters 

---------- 

config : `lsst.skymap.BaseSkyMapConfig` (optional) 

The configuration for this SkyMap; if None use the default config. 

""" 

ConfigClass = DodecaSkyMapConfig 

_version = (1, 0) # for pickle 

 

def __init__(self, config=None): 

BaseSkyMap.__init__(self, config) 

self._dodecahedron = detail.Dodecahedron(withFacesOnPoles=self.config.withTractsOnPoles) 

 

tractOverlap = geom.Angle(self.config.tractOverlap, geom.degrees) 

 

for id in range(12): 

tractVec = self._dodecahedron.getFaceCtr(id) 

tractCoord = detail.coordFromVec(tractVec, defRA=geom.Angle(0)) 

tractRA = tractCoord.getLongitude() 

vertexVecList = self._dodecahedron.getVertices(id) 

 

# make initial WCS; don't worry about crPixPos because TractInfo will shift it as required 

wcs = self._wcsFactory.makeWcs(crPixPos=geom.Point2D(0, 0), crValCoord=tractCoord) 

 

self._tractInfoList.append( 

TractInfo( 

id=id, 

patchInnerDimensions=self.config.patchInnerDimensions, 

patchBorder=self.config.patchBorder, 

ctrCoord=tractCoord, 

vertexCoordList=[detail.coordFromVec(vec, defRA=tractRA) for vec in vertexVecList], 

tractOverlap=tractOverlap, 

wcs=wcs, 

) 

) 

 

def __getstate__(self): 

"""Support pickle. 

 

Returns 

------- 

result : `dict` 

A dict containing: 

- version: a pair of ints 

- config: the config 

""" 

return dict( 

version=self._version, 

config=self.config, 

) 

 

def __setstate__(self, stateDict): 

"""Support unpickle 

 

Parameters 

---------- 

stateDict : `dict` 

- version: a pair of ints 

- config: the config 

""" 

version = stateDict["version"] 

if version >= (2, 0): 

raise RuntimeError("Version = %s >= (2,0); cannot unpickle" % (version,)) 

self.__init__(stateDict["config"]) 

 

def findTract(self, coord): 

"""Find the tract whose inner region includes the coord. 

 

Parameters 

---------- 

coord : `lsst.geom.SpherePoint` 

ICRS sky coordinate to search for. 

 

Returns 

------- 

tractInfo : `TractInfo` 

Info for tract whose inner region includes the coord. 

""" 

return self[self._dodecahedron.getFaceInd(coord.getVector())] 

 

def getVersion(self): 

"""Return version (e.g. for pickle). 

 

Returns 

------- 

version : `tuple` of `int` 

Version as a pair of integers. 

""" 

return self._version 

 

def getWithTractsOnPoles(self): 

"""Return True if there are tracts centered on the poles. 

""" 

return self._dodecahedron.getWithFacesOnPoles() 

 

def updateSha1(self, sha1): 

"""Add subclass-specific state or configuration options to the SHA1.""" 

sha1.update(struct.pack("<?", self.config.withTractsOnPoles))