Coverage for python/lsst/skymap/baseSkyMap.py: 24%

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1# LSST Data Management System 

2# Copyright 2008, 2009, 2010 LSST Corporation. 

3# 

4# This product includes software developed by the 

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

6# 

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

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

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

10# (at your option) any later version. 

11# 

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

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

14# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 

15# GNU General Public License for more details. 

16# 

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

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

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

20# 

21 

22""" 

23todo: Consider tweaking pixel scale so the average scale is as specified, 

24rather than the scale at the center. 

25""" 

26 

27__all__ = ["BaseSkyMapConfig", "BaseSkyMap"] 

28 

29import hashlib 

30import numpy as np 

31 

32import lsst.geom as geom 

33import lsst.pex.config as pexConfig 

34from lsst.geom import Angle, arcseconds, degrees 

35from . import detail 

36from .tractBuilder import tractBuilderRegistry 

37 

38 

39class BaseSkyMapConfig(pexConfig.Config): 

40 tractBuilder = tractBuilderRegistry.makeField( 

41 doc="Algorithm for creating patches within the tract.", 

42 default="legacy" 

43 ) 

44 

45 tractOverlap = pexConfig.Field( 

46 doc="minimum overlap between adjacent sky tracts, on the sky (deg)", 

47 dtype=float, 

48 default=1.0, 

49 ) 

50 pixelScale = pexConfig.Field( 

51 doc="nominal pixel scale (arcsec/pixel)", 

52 dtype=float, 

53 default=0.333 

54 ) 

55 projection = pexConfig.Field( 

56 doc="one of the FITS WCS projection codes, such as:" 

57 "- STG: stereographic projection" 

58 "- MOL: Molleweide's projection" 

59 "- TAN: tangent-plane projection", 

60 dtype=str, 

61 default="STG", 

62 ) 

63 rotation = pexConfig.Field( 

64 doc="Rotation for WCS (deg)", 

65 dtype=float, 

66 default=0, 

67 ) 

68 

69 # Backwards compatibility 

70 # We can't use the @property decorator because it makes pexConfig sad. 

71 def getPatchInnerDimensions(self): 

72 """Get the patch inner dimensions, for backwards compatibility. 

73 

74 This value is only used with the ``legacy`` tract builder, 

75 and is ignored otherwise. In general, the config should be 

76 accessed directly with 

77 ``config.tractBuilder["legacy"].patchInnerDimensions``. 

78 

79 Returns 

80 ------- 

81 innerDimensions : `list` [`int`, `int`] 

82 """ 

83 return self.tractBuilder["legacy"].patchInnerDimensions 

84 

85 def setPatchInnerDimensions(self, value): 

86 """Set the patch inner dimensions, for backwards compatibility. 

87 

88 This value is only used with the ``legacy`` tract builder, 

89 and is ignored otherwise. In general, the config should be 

90 accessed directly with 

91 ``config.tractBuilder["legacy"].patchInnerDimensions``. 

92 

93 Parameters 

94 ---------- 

95 value : `list` [`int`, `int`] 

96 """ 

97 self.tractBuilder["legacy"].patchInnerDimensions = value 

98 

99 patchInnerDimensions = property(getPatchInnerDimensions, setPatchInnerDimensions) 

100 

101 def getPatchBorder(self): 

102 """Get the patch border, for backwards compatibility. 

103 

104 This value is only used with the ``legacy`` tract builder, 

105 and is ignored otherwise. In general, the config should be 

106 accessed directly with config.tractBuilder["legacy"].patchBorder. 

107 

108 Returns 

109 ------- 

110 border: `int` 

111 """ 

112 return self.tractBuilder["legacy"].patchBorder 

113 

114 def setPatchBorder(self, value): 

115 """Set the patch border, for backwards compatibility. 

116 

117 This value is only used with the ``legacy`` tract builder, 

118 and is ignored otherwise. In general, the config should be 

119 accessed directly with config.tractBuilder["legacy"].patchBorder. 

120 

121 Parameters 

122 ---------- 

123 border: `int` 

124 """ 

125 self.tractBuilder["legacy"].patchBorder = value 

126 

127 patchBorder = property(getPatchBorder, setPatchBorder) 

128 

129 

130class BaseSkyMap: 

131 """A collection of overlapping Tracts that map part or all of the sky. 

132 

133 See TractInfo for more information. 

134 

135 Parameters 

136 ---------- 

137 config : `BaseSkyMapConfig` or `None` (optional) 

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

139 

140 Notes 

141 ----- 

142 BaseSkyMap is an abstract base class. Subclasses must do the following: 

143 define ``__init__`` and have it construct the TractInfo objects and put 

144 them in ``__tractInfoList__`` define ``__getstate__`` and ``__setstate__`` 

145 to allow pickling (the butler saves sky maps using pickle); 

146 see DodecaSkyMap for an example of how to do this. (Most of that code could 

147 be moved into this base class, but that would make it harder to handle 

148 older versions of pickle data.) define updateSha1 to add any 

149 subclass-specific state to the hash. 

150 

151 All SkyMap subclasses must be conceptually immutable; they must always 

152 refer to the same set of mathematical tracts and patches even if the in- 

153 memory representation of those objects changes. 

154 """ 

155 

156 ConfigClass = BaseSkyMapConfig 

157 

158 def __init__(self, config=None): 

159 if config is None: 

160 config = self.ConfigClass() 

161 config.freeze() # just to be sure, e.g. for pickling 

162 self.config = config 

163 self._tractInfoList = [] 

164 self._wcsFactory = detail.WcsFactory( 

165 pixelScale=Angle(self.config.pixelScale, arcseconds), 

166 projection=self.config.projection, 

167 rotation=Angle(self.config.rotation, degrees), 

168 ) 

169 self._sha1 = None 

170 self._tractBuilder = config.tractBuilder.apply() 

171 

172 def findTract(self, coord): 

173 """Find the tract whose center is nearest the specified coord. 

174 

175 Parameters 

176 ---------- 

177 coord : `lsst.geom.SpherePoint` 

178 ICRS sky coordinate to search for. 

179 

180 Returns 

181 ------- 

182 result : `TractInfo` 

183 TractInfo of tract whose center is nearest the specified coord. 

184 

185 Notes 

186 ----- 

187 - If coord is equidistant between multiple sky tract centers then one 

188 is arbitrarily chosen. 

189 

190 - The default implementation is not very efficient; subclasses may wish 

191 to override. 

192 

193 .. warning:: 

194 

195 If tracts do not cover the whole sky then the returned tract may not 

196 include the coord. 

197 """ 

198 distTractInfoList = [] 

199 for i, tractInfo in enumerate(self): 

200 angSep = coord.separation(tractInfo.getCtrCoord()).asDegrees() 

201 # include index in order to disambiguate identical angSep values 

202 distTractInfoList.append((angSep, i, tractInfo)) 

203 distTractInfoList.sort() 

204 return distTractInfoList[0][2] 

205 

206 def findTractIdArray(self, ra, dec, degrees=False): 

207 """Find array of tract IDs with vectorized operations (where 

208 supported). 

209 

210 If a given sky map does not support vectorized operations, then a loop 

211 over findTract will be called. 

212 

213 Parameters 

214 ---------- 

215 ra : `numpy.ndarray` 

216 Array of Right Ascension. Units are radians unless 

217 degrees=True. 

218 dec : `numpy.ndarray` 

219 Array of Declination. Units are radians unless 

220 degrees=True. 

221 degrees : `bool`, optional 

222 Input ra, dec arrays are degrees if `True`. 

223 

224 Returns 

225 ------- 

226 tractId : `numpy.ndarray` 

227 Array of tract IDs 

228 

229 Notes 

230 ----- 

231 - If coord is equidistant between multiple sky tract centers then one 

232 is arbitrarily chosen. 

233 

234 .. warning:: 

235 

236 If tracts do not cover the whole sky then the returned tract may not 

237 include the given ra/dec. 

238 """ 

239 units = geom.degrees if degrees else geom.radians 

240 coords = [geom.SpherePoint(r*units, d*units) for r, d in zip(np.atleast_1d(ra), 

241 np.atleast_1d(dec))] 

242 

243 tractId = np.array([self.findTract(coord).getId() for coord in coords]) 

244 

245 return tractId 

246 

247 def findTractPatchList(self, coordList): 

248 """Find tracts and patches that overlap a region. 

249 

250 Parameters 

251 ---------- 

252 coordList : `list` of `lsst.geom.SpherePoint` 

253 List of ICRS sky coordinates to search for. 

254 

255 Returns 

256 ------- 

257 reList : `list` of (`TractInfo`, `list` of `PatchInfo`) 

258 For tracts and patches that contain, or may contain, the specified 

259 region. The list will be empty if there is no overlap. 

260 

261 Notes 

262 ----- 

263 .. warning:: 

264 

265 This uses a naive algorithm that may find some tracts and patches 

266 that do not overlap the region (especially if the region is not a 

267 rectangle aligned along patch x, y). 

268 """ 

269 retList = [] 

270 for tractInfo in self: 

271 patchList = tractInfo.findPatchList(coordList) 

272 if patchList: 

273 retList.append((tractInfo, patchList)) 

274 return retList 

275 

276 def findClosestTractPatchList(self, coordList): 

277 """Find closest tract and patches that overlap coordinates. 

278 

279 Parameters 

280 ---------- 

281 coordList : `lsst.geom.SpherePoint` 

282 List of ICRS sky coordinates to search for. 

283 

284 Returns 

285 ------- 

286 retList : `list` 

287 list of (TractInfo, list of PatchInfo) for tracts and patches 

288 that contain, or may contain, the specified region. 

289 The list will be empty if there is no overlap. 

290 """ 

291 retList = [] 

292 for coord in coordList: 

293 tractInfo = self.findTract(coord) 

294 patchList = tractInfo.findPatchList(coordList) 

295 if patchList and not (tractInfo, patchList) in retList: 

296 retList.append((tractInfo, patchList)) 

297 return retList 

298 

299 def __getitem__(self, ind): 

300 return self._tractInfoList[ind] 

301 

302 def __iter__(self): 

303 return iter(self._tractInfoList) 

304 

305 def __len__(self): 

306 return len(self._tractInfoList) 

307 

308 def __hash__(self): 

309 return hash(self.getSha1()) 

310 

311 def __eq__(self, other): 

312 try: 

313 return self.getSha1() == other.getSha1() 

314 except AttributeError: 

315 return NotImplemented 

316 

317 def __ne__(self, other): 

318 return not (self == other) 

319 

320 def logSkyMapInfo(self, log): 

321 """Write information about a sky map to supplied log 

322 

323 Parameters 

324 ---------- 

325 log : `logging.Logger` 

326 Log object that information about skymap will be written. 

327 """ 

328 log.info("sky map has %s tracts" % (len(self),)) 

329 for tractInfo in self: 

330 wcs = tractInfo.getWcs() 

331 posBox = geom.Box2D(tractInfo.getBBox()) 

332 pixelPosList = ( 

333 posBox.getMin(), 

334 geom.Point2D(posBox.getMaxX(), posBox.getMinY()), 

335 posBox.getMax(), 

336 geom.Point2D(posBox.getMinX(), posBox.getMaxY()), 

337 ) 

338 skyPosList = [wcs.pixelToSky(pos).getPosition(geom.degrees) for pos in pixelPosList] 

339 posStrList = ["(%0.3f, %0.3f)" % tuple(skyPos) for skyPos in skyPosList] 

340 log.info("tract %s has corners %s (RA, Dec deg) and %s x %s patches" % 

341 (tractInfo.getId(), ", ".join(posStrList), 

342 tractInfo.getNumPatches()[0], tractInfo.getNumPatches()[1])) 

343 

344 def getSha1(self): 

345 """Return a SHA1 hash that uniquely identifies this SkyMap instance. 

346 

347 Returns 

348 ------- 

349 sha1 : `bytes` 

350 A 20-byte hash that uniquely identifies this SkyMap instance. 

351 

352 Notes 

353 ----- 

354 Subclasses should almost always override ``updateSha1`` instead of 

355 this function to add subclass-specific state to the hash. 

356 """ 

357 if self._sha1 is None: 

358 sha1 = hashlib.sha1() 

359 sha1.update(type(self).__name__.encode('utf-8')) 

360 configPacked = self._tractBuilder.getPackedConfig(self.config) 

361 sha1.update(configPacked) 

362 self.updateSha1(sha1) 

363 self._sha1 = sha1.digest() 

364 return self._sha1 

365 

366 def updateSha1(self, sha1): 

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

368 

369 Parameters 

370 ---------- 

371 sha1 : `hashlib.sha1` 

372 A hashlib object on which `update` can be called to add 

373 additional state to the hash. 

374 

375 Notes 

376 ----- 

377 This method is conceptually "protected" : it should be reimplemented by 

378 all subclasses, but called only by the base class implementation of 

379 `getSha1` . 

380 """ 

381 raise NotImplementedError() 

382 

383 SKYMAP_RUN_COLLECTION_NAME = "skymaps" 

384 

385 SKYMAP_DATASET_TYPE_NAME = "skyMap" 

386 

387 def register(self, name, butler): 

388 """Add skymap, tract, and patch Dimension entries to the given Gen3 

389 Butler. 

390 

391 Parameters 

392 ---------- 

393 name : `str` 

394 The name of the skymap. 

395 butler : `lsst.daf.butler.Butler` 

396 The butler to add to. 

397 

398 Raises 

399 ------ 

400 lsst.daf.butler.registry.ConflictingDefinitionError 

401 Raised if a different skymap exists with the same name. 

402 

403 Notes 

404 ----- 

405 Registering the same skymap multiple times (with the exact same 

406 definition) is safe, but inefficient; most of the work of computing 

407 the rows to be inserted must be done first in order to check for 

408 consistency between the new skymap and any existing one. 

409 

410 Re-registering a skymap with different tract and/or patch definitions 

411 but the same summary information may not be detected as a conflict but 

412 will never result in updating the skymap; there is intentionally no 

413 way to modify a registered skymap (aside from manual administrative 

414 operations on the database), as it is hard to guarantee that this can 

415 be done without affecting reproducibility. 

416 """ 

417 numPatches = [tractInfo.getNumPatches() for tractInfo in self] 

418 nxMax = max(nn[0] for nn in numPatches) 

419 nyMax = max(nn[1] for nn in numPatches) 

420 

421 skyMapRecord = { 

422 "skymap": name, 

423 "hash": self.getSha1(), 

424 "tract_max": len(self), 

425 "patch_nx_max": nxMax, 

426 "patch_ny_max": nyMax, 

427 } 

428 butler.registry.registerRun(self.SKYMAP_RUN_COLLECTION_NAME) 

429 # Kind of crazy that we've got three different capitalizations of 

430 # "skymap" here, but that's what the various conventions (or at least 

431 # precedents) dictate. 

432 from lsst.daf.butler import DatasetType 

433 from lsst.daf.butler.registry import ConflictingDefinitionError 

434 datasetType = DatasetType( 

435 name=self.SKYMAP_DATASET_TYPE_NAME, 

436 dimensions=["skymap"], 

437 storageClass="SkyMap", 

438 universe=butler.dimensions 

439 ) 

440 butler.registry.registerDatasetType(datasetType) 

441 with butler.transaction(): 

442 try: 

443 inserted = butler.registry.syncDimensionData("skymap", skyMapRecord) 

444 except ConflictingDefinitionError as err: 

445 raise ConflictingDefinitionError( 

446 f"SkyMap with hash {self.getSha1().hex()} is already registered with a different name." 

447 ) from err 

448 if inserted: 

449 for tractInfo in self: 

450 tractId = tractInfo.getId() 

451 tractRegion = tractInfo.getOuterSkyPolygon() 

452 tractWcs = tractInfo.getWcs() 

453 tractRecord = dict( 

454 skymap=name, 

455 tract=tractId, 

456 region=tractRegion, 

457 ) 

458 butler.registry.insertDimensionData("tract", tractRecord) 

459 

460 patchRecords = [] 

461 for patchInfo in tractInfo: 

462 xx, yy = patchInfo.getIndex() 

463 patchRecords.append( 

464 dict( 

465 skymap=name, 

466 tract=tractId, 

467 patch=tractInfo.getSequentialPatchIndex(patchInfo), 

468 cell_x=xx, 

469 cell_y=yy, 

470 region=patchInfo.getOuterSkyPolygon(tractWcs), 

471 ) 

472 ) 

473 butler.registry.insertDimensionData("patch", *patchRecords) 

474 

475 butler.put(self, datasetType, {"skymap": name}, run=self.SKYMAP_RUN_COLLECTION_NAME)