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1from builtins import zip 

2from builtins import range 

3# The base class for all spatial slicers. 

4# Slicers are 'data slicers' at heart; spatial slicers slice data by RA/Dec and 

5# return the relevant indices in the simData to the metric. 

6# The primary things added here are the methods to slice the data (for any spatial slicer) 

7# as this uses a KD-tree built on spatial (RA/Dec type) indexes. 

8 

9import warnings 

10import numpy as np 

11from functools import wraps 

12from lsst.sims.maf.plots.spatialPlotters import BaseHistogram, BaseSkyMap 

13 

14# For the footprint generation and conversion between galactic/equatorial coordinates. 

15from lsst.obs.lsstSim import LsstSimMapper 

16from lsst.sims.coordUtils import _chipNameFromRaDec 

17import lsst.sims.utils as simsUtils 

18 

19from .baseSlicer import BaseSlicer 

20 

21__all__ = ['BaseSpatialSlicer'] 

22 

23 

24class BaseSpatialSlicer(BaseSlicer): 

25 """Base spatial slicer object, contains additional functionality for spatial slicing, 

26 including setting up and traversing a kdtree containing the simulated data points. 

27 

28 Parameters 

29 ---------- 

30 lonCol : str, optional 

31 Name of the longitude (RA equivalent) column to use from the input data. 

32 Default fieldRA 

33 latCol : str, optional 

34 Name of the latitude (Dec equivalent) column to use from the input data. 

35 Default fieldDec 

36 latLonDeg : boolean, optional 

37 Flag indicating whether lat and lon values from input data are in degrees (True) or radians (False). 

38 Default True. 

39 verbose : boolean, optional 

40 Flag to indicate whether or not to write additional information to stdout during runtime. 

41 Default True. 

42 badval : float, optional 

43 Bad value flag, relevant for plotting. Default -666. 

44 leafsize : int, optional 

45 Leafsize value for kdtree. Default 100. 

46 radius : float, optional 

47 Radius for matching in the kdtree. Equivalent to the radius of the FOV. Degrees. 

48 Default 1.75. 

49 useCamera : boolean, optional 

50 Flag to indicate whether to use the LSST camera footprint or not. 

51 Default False. 

52 rotSkyPosColName : str, optional 

53 Name of the rotSkyPos column in the input data. Only used if useCamera is True. 

54 Describes the orientation of the camera orientation compared to the sky. 

55 Default rotSkyPos. 

56 mjdColName : str, optional 

57 Name of the exposure time column. Only used if useCamera is True. 

58 Default observationStartMJD. 

59 chipNames : array-like, optional 

60 List of chips to accept, if useCamera is True. This lets users turn 'on' only a subset of chips. 

61 Default 'all' - this uses all chips in the camera. 

62 """ 

63 def __init__(self, lonCol='fieldRA', latCol='fieldDec', latLonDeg=True, 

64 verbose=True, badval=-666, leafsize=100, radius=1.75, 

65 useCamera=False, rotSkyPosColName='rotSkyPos', mjdColName='observationStartMJD', 

66 chipNames='all'): 

67 super(BaseSpatialSlicer, self).__init__(verbose=verbose, badval=badval) 

68 self.lonCol = lonCol 

69 self.latCol = latCol 

70 self.latLonDeg = latLonDeg 

71 self.rotSkyPosColName = rotSkyPosColName 

72 self.mjdColName = mjdColName 

73 self.columnsNeeded = [lonCol, latCol] 

74 self.useCamera = useCamera 

75 if useCamera: 

76 self.columnsNeeded.append(rotSkyPosColName) 

77 self.columnsNeeded.append(mjdColName) 

78 self.slicer_init = {'lonCol': lonCol, 'latCol': latCol, 

79 'radius': radius, 'badval': badval, 

80 'useCamera': useCamera} 

81 self.radius = radius 

82 self.leafsize = leafsize 

83 self.useCamera = useCamera 

84 self.chipsToUse = chipNames 

85 # RA and Dec are required slicePoint info for any spatial slicer. Slicepoint RA/Dec are in radians. 

86 self.slicePoints['sid'] = None 

87 self.slicePoints['ra'] = None 

88 self.slicePoints['dec'] = None 

89 self.nslice = None 

90 self.shape = None 

91 self.plotFuncs = [BaseHistogram, BaseSkyMap] 

92 

93 def setupSlicer(self, simData, maps=None): 

94 """Use simData[self.lonCol] and simData[self.latCol] (in radians) to set up KDTree. 

95 

96 Parameters 

97 ----------- 

98 simData : numpy.recarray 

99 The simulated data, including the location of each pointing. 

100 maps : list of lsst.sims.maf.maps objects, optional 

101 List of maps (such as dust extinction) that will run to build up additional metadata at each 

102 slicePoint. This additional metadata is available to metrics via the slicePoint dictionary. 

103 Default None. 

104 """ 

105 if maps is not None: 

106 if self.cacheSize != 0 and len(maps) > 0: 

107 warnings.warn('Warning: Loading maps but cache on.' 

108 'Should probably set useCache=False in slicer.') 

109 self._runMaps(maps) 

110 self._setRad(self.radius) 

111 if self.useCamera: 

112 self._setupLSSTCamera() 

113 self._presliceFootprint(simData) 

114 else: 

115 if self.latLonDeg: 

116 self._buildTree(np.radians(simData[self.lonCol]), 

117 np.radians(simData[self.latCol]), self.leafsize) 

118 else: 

119 self._buildTree(simData[self.lonCol], simData[self.latCol], self.leafsize) 

120 

121 @wraps(self._sliceSimData) 

122 def _sliceSimData(islice): 

123 """Return indexes for relevant opsim data at slicepoint 

124 (slicepoint=lonCol/latCol value .. usually ra/dec).""" 

125 

126 # Build dict for slicePoint info 

127 slicePoint = {} 

128 if self.useCamera: 

129 indices = self.sliceLookup[islice] 

130 slicePoint['chipNames'] = self.chipNames[islice] 

131 else: 

132 sx, sy, sz = simsUtils._xyz_from_ra_dec(self.slicePoints['ra'][islice], 

133 self.slicePoints['dec'][islice]) 

134 # Query against tree. 

135 indices = self.opsimtree.query_ball_point((sx, sy, sz), self.rad) 

136 

137 # Loop through all the slicePoint keys. If the first dimension of slicepoint[key] has 

138 # the same shape as the slicer, assume it is information per slicepoint. 

139 # Otherwise, pass the whole slicePoint[key] information. Useful for stellar LF maps 

140 # where we want to pass only the relevant LF and the bins that go with it. 

141 for key in self.slicePoints: 

142 if len(np.shape(self.slicePoints[key])) == 0: 

143 keyShape = 0 

144 else: 

145 keyShape = np.shape(self.slicePoints[key])[0] 

146 if (keyShape == self.nslice): 

147 slicePoint[key] = self.slicePoints[key][islice] 

148 else: 

149 slicePoint[key] = self.slicePoints[key] 

150 return {'idxs': indices, 'slicePoint': slicePoint} 

151 setattr(self, '_sliceSimData', _sliceSimData) 

152 

153 def _setupLSSTCamera(self): 

154 """If we want to include the camera chip gaps, etc""" 

155 mapper = LsstSimMapper() 

156 self.camera = mapper.camera 

157 self.epoch = 2000.0 

158 

159 def _presliceFootprint(self, simData): 

160 """Loop over each pointing and find which sky points are observed """ 

161 # Now to make a list of lists for looking up the relevant observations at each slicepoint 

162 self.sliceLookup = [[] for dummy in range(self.nslice)] 

163 self.chipNames = [[] for dummy in range(self.nslice)] 

164 # Make a kdtree for the _slicepoints_ 

165 # Using scipy 0.16 or later 

166 self._buildTree(self.slicePoints['ra'], self.slicePoints['dec'], leafsize=self.leafsize) 

167 

168 # Loop over each unique pointing position 

169 if self.latLonDeg: 

170 lat = np.radians(simData[self.latCol]) 

171 lon = np.radians(simData[self.lonCol]) 

172 else: 

173 lat = simData[self.latCol] 

174 lon = simData[self.lonCol] 

175 for ind, ra, dec, rotSkyPos, mjd in zip(np.arange(simData.size), lon, lat, 

176 simData[self.rotSkyPosColName], simData[self.mjdColName]): 

177 dx, dy, dz = simsUtils._xyz_from_ra_dec(ra, dec) 

178 # Find healpixels inside the FoV 

179 hpIndices = np.array(self.opsimtree.query_ball_point((dx, dy, dz), self.rad)) 

180 if hpIndices.size > 0: 

181 obs_metadata = simsUtils.ObservationMetaData(pointingRA=np.degrees(ra), 

182 pointingDec=np.degrees(dec), 

183 rotSkyPos=np.degrees(rotSkyPos), 

184 mjd=mjd) 

185 

186 chipNames = _chipNameFromRaDec(self.slicePoints['ra'][hpIndices], 

187 self.slicePoints['dec'][hpIndices], 

188 epoch=self.epoch, 

189 camera=self.camera, obs_metadata=obs_metadata) 

190 # If we are using only a subset of chips 

191 if self.chipsToUse != 'all': 

192 checkedChipNames = [chipName in self.chipsToUse for chipName in chipNames] 

193 good = np.where(checkedChipNames)[0] 

194 chipNames = chipNames[good] 

195 hpIndices = hpIndices[good] 

196 # Find the healpixels that fell on a chip for this pointing 

197 good = np.where(chipNames != [None])[0] 

198 hpOnChip = hpIndices[good] 

199 for i, chipName in zip(hpOnChip, chipNames[good]): 

200 self.sliceLookup[i].append(ind) 

201 self.chipNames[i].append(chipName) 

202 

203 if self.verbose: 

204 "Created lookup table after checking for chip gaps." 

205 

206 def _buildTree(self, simDataRa, simDataDec, leafsize=100): 

207 """Build KD tree on simDataRA/Dec using utility function from mafUtils. 

208 

209 simDataRA, simDataDec = RA and Dec values (in radians). 

210 leafsize = the number of Ra/Dec pointings in each leaf node.""" 

211 self.opsimtree = simsUtils._buildTree(simDataRa, 

212 simDataDec, 

213 leafsize) 

214 

215 def _setRad(self, radius=1.75): 

216 """Set radius (in degrees) for kdtree search using utility function from mafUtils.""" 

217 self.rad = simsUtils.xyz_angular_radius(radius)