Inheritance diagram for lsst.skymap.tractInfo.TractInfo:
Public Member Functions | |
| __init__ (self, id, tractBuilder, ctrCoord, vertexCoordList, tractOverlap, wcs) | |
| getSequentialPatchIndex (self, patchInfo) | |
| getSequentialPatchIndexFromPair (self, index) | |
| getPatchIndexPair (self, sequentialIndex) | |
| findPatch (self, coord) | |
| findPatchList (self, coordList) | |
| getBBox (self) | |
| getCtrCoord (self) | |
| getId (self) | |
| getNumPatches (self) | |
| getPatchBorder (self) | |
| getPatchInfo (self, index) | |
| getPatchInnerDimensions (self) | |
| getTractOverlap (self) | |
| getVertexList (self) | |
| getInnerSkyPolygon (self) | |
| getOuterSkyPolygon (self) | |
| getWcs (self) | |
| __str__ (self) | |
| __repr__ (self) | |
| __iter__ (self) | |
| __len__ (self) | |
| __getitem__ (self, index) | |
| contains (self, coord) | |
Protected Member Functions | |
| _minimumBoundingBox (self, wcs) | |
| _finalOrientation (self, bbox, wcs) | |
Protected Attributes | |
| _id | |
| _ctrCoord | |
| _vertexCoordList | |
| _tractOverlap | |
| _tractBuilder | |
| _numPatches | |
| _bbox | |
| _wcs | |
Properties | |
| bbox = property(getBBox) | |
| ctr_coord = property(getCtrCoord) | |
| tract_id = property(getId) | |
| num_patches = property(getNumPatches) | |
| patch_border = property(getPatchBorder) | |
| patch_inner_dimensions = property(getPatchInnerDimensions) | |
| tract_overlap = property(getTractOverlap) | |
| vertex_list = property(getVertexList) | |
| inner_sky_polygon = property(getInnerSkyPolygon) | |
| outer_sky_polygon = property(getOuterSkyPolygon) | |
| wcs = property(getWcs) | |
Detailed Description
Information about a tract in a SkyMap sky pixelization
Parameters
----------
id : `int`
tract ID
tractBuilder : Subclass of `lsst.skymap.BaseTractBuilder`
Object used to compute patch geometry.
ctrCoord : `lsst.geom.SpherePoint`
ICRS sky coordinate of center of inner region of tract; also used as
the CRVAL for the WCS.
vertexCoordList : `list` of `lsst.geom.SpherePoint`
Vertices that define the boundaries of the inner region.
tractOverlap : `lsst.geom.Angle`
Minimum overlap between adjacent sky tracts; this defines the minimum
distance the tract extends beyond the inner region in all directions.
wcs : `lsst.afw.image.SkyWcs`
WCS for tract. The reference pixel will be shifted as required so that
the lower left-hand pixel (index 0,0) has pixel position 0.0, 0.0.
Notes
-----
The tract is subdivided into rectangular patches. Each patch has the
following properties:
- An inner region defined by an inner bounding box. The inner regions of
the patches exactly tile the tract, and all inner regions have the same
dimensions. The tract is made larger as required to make this work.
- An outer region defined by an outer bounding box. The outer region
extends beyond the inner region by patchBorder pixels in all directions,
except there is no border at the edges of the tract.
Thus patches overlap each other but never extend off the tract.
If you do not want any overlap between adjacent patches then set
patchBorder to 0.
- An index that consists of a pair of integers:
* 0 <= x index < numPatches[0]
* 0 <= y index < numPatches[1]
Patch 0,0 is at the minimum corner of the tract bounding box.
- It is not enforced that ctrCoord is the center of vertexCoordList, but
SkyMap relies on it.
Definition at line 34 of file tractInfo.py.
Constructor & Destructor Documentation
◆ __init__()
| lsst.skymap.tractInfo.TractInfo.__init__ | ( | self, | |
| id, | |||
| tractBuilder, | |||
| ctrCoord, | |||
| vertexCoordList, | |||
| tractOverlap, | |||
| wcs ) |
Reimplemented in lsst.skymap.tractInfo.ExplicitTractInfo, and lsst.skymap.healpixSkyMap.HealpixTractInfo.
Definition at line 82 of file tractInfo.py.
82 def __init__(self, id, tractBuilder, ctrCoord, vertexCoordList, tractOverlap, wcs):
83 self._id = id
84 self._ctrCoord = ctrCoord
85 self._vertexCoordList = tuple(vertexCoordList)
86 self._tractOverlap = tractOverlap
87 self._tractBuilder = tractBuilder
88
89 minBBox = self._minimumBoundingBox(wcs)
90 initialBBox, self._numPatches = self._tractBuilder.setupPatches(minBBox, wcs)
91 self._bbox, self._wcs = self._finalOrientation(initialBBox, wcs)
92
Member Function Documentation
◆ __getitem__()
| lsst.skymap.tractInfo.TractInfo.__getitem__ | ( | self, | |
| index ) |
Definition at line 394 of file tractInfo.py.
394 def __getitem__(self, index):
395 return self.getPatchInfo(index)
396
◆ __iter__()
| lsst.skymap.tractInfo.TractInfo.__iter__ | ( | self | ) |
Definition at line 384 of file tractInfo.py.
384 def __iter__(self):
385 xNum, yNum = self.getNumPatches()
386 for y in range(yNum):
387 for x in range(xNum):
388 yield self.getPatchInfo(Index2D(x=x, y=y))
389
◆ __len__()
| lsst.skymap.tractInfo.TractInfo.__len__ | ( | self | ) |
Definition at line 390 of file tractInfo.py.
390 def __len__(self):
391 xNum, yNum = self.getNumPatches()
392 return xNum*yNum
393
◆ __repr__()
| lsst.skymap.tractInfo.TractInfo.__repr__ | ( | self | ) |
Definition at line 381 of file tractInfo.py.
381 def __repr__(self):
382 return "TractInfo(id=%s, ctrCoord=%s)" % (self._id, self._ctrCoord.getVector())
383
◆ __str__()
| lsst.skymap.tractInfo.TractInfo.__str__ | ( | self | ) |
Definition at line 378 of file tractInfo.py.
378 def __str__(self):
379 return "TractInfo(id=%s)" % (self._id,)
380
◆ _finalOrientation()
|
protected |
Determine the final orientation
We offset everything so the lower-left corner is at 0,0
and compute the final Wcs.
Parameters
----------
bbox : `lsst.geom.Box2I`
Current bounding box.
wcs : `lsst.afw.geom.SkyWcs
Current Wcs.
Returns
-------
finalBBox : `lsst.geom.Box2I`
Revised bounding box.
wcs : `lsst.afw.geom.SkyWcs`
Revised Wcs.
Definition at line 117 of file tractInfo.py.
117 def _finalOrientation(self, bbox, wcs):
118 """Determine the final orientation
119
120 We offset everything so the lower-left corner is at 0,0
121 and compute the final Wcs.
122
123 Parameters
124 ----------
125 bbox : `lsst.geom.Box2I`
126 Current bounding box.
127 wcs : `lsst.afw.geom.SkyWcs
128 Current Wcs.
129
130 Returns
131 -------
132 finalBBox : `lsst.geom.Box2I`
133 Revised bounding box.
134 wcs : `lsst.afw.geom.SkyWcs`
135 Revised Wcs.
136 """
138 # shift the WCS by the same amount as the bbox; extra code is required
139 # because simply subtracting makes an Extent2I
140 pixPosOffset = geom.Extent2D(finalBBox.getMinX() - bbox.getMinX(),
141 finalBBox.getMinY() - bbox.getMinY())
142 wcs = wcs.copyAtShiftedPixelOrigin(pixPosOffset)
143 return finalBBox, wcs
144
◆ _minimumBoundingBox()
|
protected |
Calculate the minimum bounding box for the tract, given the WCS. The bounding box is created in the frame of the supplied WCS, so that it's OK if the coordinates are negative. We compute the bounding box that holds all the vertices and the desired overlap.
Reimplemented in lsst.skymap.tractInfo.ExplicitTractInfo.
Definition at line 93 of file tractInfo.py.
93 def _minimumBoundingBox(self, wcs):
94 """Calculate the minimum bounding box for the tract, given the WCS.
95
96 The bounding box is created in the frame of the supplied WCS,
97 so that it's OK if the coordinates are negative.
98
99 We compute the bounding box that holds all the vertices and the
100 desired overlap.
101 """
102 minBBoxD = geom.Box2D()
103 halfOverlap = self._tractOverlap / 2.0
104 for vertexCoord in self._vertexCoordList:
105 if self._tractOverlap == 0:
106 minBBoxD.include(wcs.skyToPixel(vertexCoord))
107 else:
108 numAngles = 24
109 angleIncr = geom.Angle(360.0, geom.degrees) / float(numAngles)
110 for i in range(numAngles):
111 offAngle = angleIncr * i
112 offCoord = vertexCoord.offset(offAngle, halfOverlap)
113 pixPos = wcs.skyToPixel(offCoord)
114 minBBoxD.include(pixPos)
115 return minBBoxD
116
◆ contains()
| lsst.skymap.tractInfo.TractInfo.contains | ( | self, | |
| coord ) |
Does this tract contain the coordinate?
Definition at line 397 of file tractInfo.py.
397 def contains(self, coord):
398 """Does this tract contain the coordinate?"""
399 try:
400 pixel = self.getWcs().skyToPixel(coord)
402 # Point must be way off the tract
403 return False
404 if not np.isfinite(pixel.getX()) or not np.isfinite(pixel.getY()):
405 # Point is definitely off the tract
406 return False
408
409
Reports arguments outside the domain of an operation.
Definition Runtime.h:57
Reports errors that are due to events beyond the control of the program.
Definition Runtime.h:104
◆ findPatch()
| lsst.skymap.tractInfo.TractInfo.findPatch | ( | self, | |
| coord ) |
Find the patch containing the specified coord.
Parameters
----------
coord : `lsst.geom.SpherePoint`
ICRS sky coordinate to search for.
Returns
-------
result : `lsst.skymap.PatchInfo`
PatchInfo of patch whose inner bbox contains the specified coord
Raises
------
LookupError
Raised if coord is not in tract or we cannot determine the
pixel coordinate (which likely means the coord is off the tract).
Definition at line 186 of file tractInfo.py.
186 def findPatch(self, coord):
187 """Find the patch containing the specified coord.
188
189 Parameters
190 ----------
191 coord : `lsst.geom.SpherePoint`
192 ICRS sky coordinate to search for.
193
194 Returns
195 -------
196 result : `lsst.skymap.PatchInfo`
197 PatchInfo of patch whose inner bbox contains the specified coord
198
199 Raises
200 ------
201 LookupError
202 Raised if coord is not in tract or we cannot determine the
203 pixel coordinate (which likely means the coord is off the tract).
204 """
205 try:
206 pixel = self.wcs.skyToPixel(coord)
208 # Point must be way off the tract
209 raise LookupError("Unable to determine pixel position for coordinate %s" % (coord,))
210 pixelInd = geom.Point2I(pixel)
211 if not self._bbox.contains(pixelInd):
212 raise LookupError("coord %s is not in tract %s" % (coord, self.tract_id))
213 # This should probably be the same as above because we only
214 # care about the INNER dimensions.
215 patchInd = tuple(int(pixelInd[i]/self.patch_inner_dimensions[i]) for i in range(2))
216 return self.getPatchInfo(patchInd)
217
◆ findPatchList()
| lsst.skymap.tractInfo.TractInfo.findPatchList | ( | self, | |
| coordList ) |
Find patches containing the specified list of coords.
Parameters
----------
coordList : `list` of `lsst.geom.SpherePoint`
ICRS sky coordinates to search for.
Returns
-------
result : `list` of `lsst.skymap.PatchInfo`
List of PatchInfo for patches that contain, or may contain, the
specified region. The list will be empty if there is no overlap.
Notes
-----
**Warning:**
- This may give incorrect answers on regions that are larger than a
tract.
- This uses a naive algorithm that may find some patches that do not
overlap the region (especially if the region is not a rectangle
aligned along patch x,y).
Definition at line 218 of file tractInfo.py.
218 def findPatchList(self, coordList):
219 """Find patches containing the specified list of coords.
220
221 Parameters
222 ----------
223 coordList : `list` of `lsst.geom.SpherePoint`
224 ICRS sky coordinates to search for.
225
226 Returns
227 -------
228 result : `list` of `lsst.skymap.PatchInfo`
229 List of PatchInfo for patches that contain, or may contain, the
230 specified region. The list will be empty if there is no overlap.
231
232 Notes
233 -----
234 **Warning:**
235
236 - This may give incorrect answers on regions that are larger than a
237 tract.
238
239 - This uses a naive algorithm that may find some patches that do not
240 overlap the region (especially if the region is not a rectangle
241 aligned along patch x,y).
242 """
243 box2D = geom.Box2D()
244 for coord in coordList:
245 try:
246 pixelPos = self.wcs.skyToPixel(coord)
248 # The point is so far off the tract that its pixel position
249 # cannot be computed.
250 continue
251 box2D.include(pixelPos)
252 bbox = geom.Box2I(box2D)
253 bbox.grow(self.getPatchBorder())
254 bbox.clip(self._bbox)
255 if bbox.isEmpty():
256 return ()
257
258 llPatchInd = tuple(int(bbox.getMin()[i]/self.patch_inner_dimensions[i]) for i in range(2))
259 urPatchInd = tuple(int(bbox.getMax()[i]/self.patch_inner_dimensions[i]) for i in range(2))
260 return tuple(self.getPatchInfo((xInd, yInd))
261 for xInd in range(llPatchInd[0], urPatchInd[0]+1)
262 for yInd in range(llPatchInd[1], urPatchInd[1]+1))
263
◆ getBBox()
| lsst.skymap.tractInfo.TractInfo.getBBox | ( | self | ) |
Get bounding box of tract (as an geom.Box2I)
Definition at line 264 of file tractInfo.py.
264 def getBBox(self):
265 """Get bounding box of tract (as an geom.Box2I)
266 """
268
◆ getCtrCoord()
| lsst.skymap.tractInfo.TractInfo.getCtrCoord | ( | self | ) |
Get ICRS sky coordinate of center of tract (as an lsst.geom.SpherePoint)
Definition at line 271 of file tractInfo.py.
271 def getCtrCoord(self):
272 """Get ICRS sky coordinate of center of tract
273 (as an lsst.geom.SpherePoint)
274 """
275 return self._ctrCoord
276
◆ getId()
| lsst.skymap.tractInfo.TractInfo.getId | ( | self | ) |
Get ID of tract
Definition at line 279 of file tractInfo.py.
279 def getId(self):
280 """Get ID of tract
281 """
282 return self._id
283
◆ getInnerSkyPolygon()
| lsst.skymap.tractInfo.TractInfo.getInnerSkyPolygon | ( | self | ) |
Get inner on-sky region as a sphgeom.ConvexPolygon.
Definition at line 351 of file tractInfo.py.
351 def getInnerSkyPolygon(self):
352 """Get inner on-sky region as a sphgeom.ConvexPolygon.
353 """
354 skyUnitVectors = [sp.getVector() for sp in self.getVertexList()]
355 return ConvexPolygon.convexHull(skyUnitVectors)
356
◆ getNumPatches()
| lsst.skymap.tractInfo.TractInfo.getNumPatches | ( | self | ) |
Get the number of patches in x, y.
Returns
-------
result : `lsst.skymap.Index2D`
The number of patches in x, y
Definition at line 286 of file tractInfo.py.
286 def getNumPatches(self):
287 """Get the number of patches in x, y.
288
289 Returns
290 -------
291 result : `lsst.skymap.Index2D`
292 The number of patches in x, y
293 """
294 return self._numPatches
295
◆ getOuterSkyPolygon()
| lsst.skymap.tractInfo.TractInfo.getOuterSkyPolygon | ( | self | ) |
Get outer on-sky region as a sphgeom.ConvexPolygon
Definition at line 359 of file tractInfo.py.
359 def getOuterSkyPolygon(self):
360 """Get outer on-sky region as a sphgeom.ConvexPolygon
361 """
362 return makeSkyPolygonFromBBox(bbox=self.getBBox(), wcs=self.getWcs())
363
◆ getPatchBorder()
| lsst.skymap.tractInfo.TractInfo.getPatchBorder | ( | self | ) |
Definition at line 298 of file tractInfo.py.
298 def getPatchBorder(self):
299 return self._tractBuilder.getPatchBorder()
300
◆ getPatchIndexPair()
| lsst.skymap.tractInfo.TractInfo.getPatchIndexPair | ( | self, | |
| sequentialIndex ) |
Convert sequential index into patch index (x,y) pair. Parameters ---------- sequentialIndex : `int` Returns ------- x, y : `lsst.skymap.Index2D`
Definition at line 173 of file tractInfo.py.
173 def getPatchIndexPair(self, sequentialIndex):
174 """Convert sequential index into patch index (x,y) pair.
175
176 Parameters
177 ----------
178 sequentialIndex : `int`
179
180 Returns
181 -------
182 x, y : `lsst.skymap.Index2D`
183 """
184 return self._tractBuilder.getPatchIndexPair(sequentialIndex)
185
◆ getPatchInfo()
| lsst.skymap.tractInfo.TractInfo.getPatchInfo | ( | self, | |
| index ) |
Return information for the specified patch.
Parameters
----------
index : `typing.NamedTuple` ['x': `int`, 'y': `int`]
Index of patch, as a pair of ints;
or a sequential index as returned by getSequentialPatchIndex;
negative values are not supported.
Returns
-------
result : `lsst.skymap.PatchInfo`
The patch info for that index.
Raises
------
IndexError
Raised if index is out of range.
Definition at line 303 of file tractInfo.py.
303 def getPatchInfo(self, index):
304 """Return information for the specified patch.
305
306 Parameters
307 ----------
308 index : `typing.NamedTuple` ['x': `int`, 'y': `int`]
309 Index of patch, as a pair of ints;
310 or a sequential index as returned by getSequentialPatchIndex;
311 negative values are not supported.
312
313 Returns
314 -------
315 result : `lsst.skymap.PatchInfo`
316 The patch info for that index.
317
318 Raises
319 ------
320 IndexError
321 Raised if index is out of range.
322 """
323 return self._tractBuilder.getPatchInfo(index, self._wcs)
324
◆ getPatchInnerDimensions()
| lsst.skymap.tractInfo.TractInfo.getPatchInnerDimensions | ( | self | ) |
Get dimensions of inner region of the patches (all are the same)
Definition at line 325 of file tractInfo.py.
325 def getPatchInnerDimensions(self):
326 """Get dimensions of inner region of the patches (all are the same)
327 """
328 return self._tractBuilder.getPatchInnerDimensions()
329
◆ getSequentialPatchIndex()
| lsst.skymap.tractInfo.TractInfo.getSequentialPatchIndex | ( | self, | |
| patchInfo ) |
Return a single integer that uniquely identifies the given patch within this tract. Parameters ---------- patchInfo : `lsst.skymap.PatchInfo` Returns ------- sequentialIndex : `int`
Definition at line 145 of file tractInfo.py.
145 def getSequentialPatchIndex(self, patchInfo):
146 """Return a single integer that uniquely identifies
147 the given patch within this tract.
148
149 Parameters
150 ----------
151 patchInfo : `lsst.skymap.PatchInfo`
152
153 Returns
154 -------
155 sequentialIndex : `int`
156 """
157 return self._tractBuilder.getSequentialPatchIndex(patchInfo)
158
◆ getSequentialPatchIndexFromPair()
| lsst.skymap.tractInfo.TractInfo.getSequentialPatchIndexFromPair | ( | self, | |
| index ) |
Return a single integer that uniquely identifies the patch index within the tract. Parameters ---------- index : `lsst.skymap.Index2D` Returns ------- sequentialIndex : `int`
Definition at line 159 of file tractInfo.py.
159 def getSequentialPatchIndexFromPair(self, index):
160 """Return a single integer that uniquely identifies
161 the patch index within the tract.
162
163 Parameters
164 ----------
165 index : `lsst.skymap.Index2D`
166
167 Returns
168 -------
169 sequentialIndex : `int`
170 """
171 return self._tractBuilder.getSequentialPatchIndexFromPair(index)
172
◆ getTractOverlap()
| lsst.skymap.tractInfo.TractInfo.getTractOverlap | ( | self | ) |
Get minimum overlap of adjacent sky tracts.
Definition at line 332 of file tractInfo.py.
332 def getTractOverlap(self):
333 """Get minimum overlap of adjacent sky tracts.
334 """
335 return self._tractOverlap
336
◆ getVertexList()
| lsst.skymap.tractInfo.TractInfo.getVertexList | ( | self | ) |
Get list of ICRS sky coordinates of vertices that define the boundary of the inner region. Notes ----- **warning:** this is not a deep copy.
Definition at line 339 of file tractInfo.py.
339 def getVertexList(self):
340 """Get list of ICRS sky coordinates of vertices that define the
341 boundary of the inner region.
342
343 Notes
344 -----
345 **warning:** this is not a deep copy.
346 """
347 return self._vertexCoordList
348
◆ getWcs()
| lsst.skymap.tractInfo.TractInfo.getWcs | ( | self | ) |
Get WCS of tract.
Returns
-------
wcs : `lsst.afw.geom.SkyWcs`
The WCS of this tract
Definition at line 366 of file tractInfo.py.
366 def getWcs(self):
367 """Get WCS of tract.
368
369 Returns
370 -------
371 wcs : `lsst.afw.geom.SkyWcs`
372 The WCS of this tract
373 """
374 return self._wcs
375
Member Data Documentation
◆ _bbox
|
protected |
Definition at line 91 of file tractInfo.py.
◆ _ctrCoord
|
protected |
Definition at line 84 of file tractInfo.py.
◆ _id
|
protected |
Definition at line 83 of file tractInfo.py.
◆ _numPatches
|
protected |
Definition at line 90 of file tractInfo.py.
◆ _tractBuilder
|
protected |
Definition at line 87 of file tractInfo.py.
◆ _tractOverlap
|
protected |
Definition at line 86 of file tractInfo.py.
◆ _vertexCoordList
|
protected |
Definition at line 85 of file tractInfo.py.
◆ _wcs
|
protected |
Definition at line 91 of file tractInfo.py.
Property Documentation
◆ bbox
|
static |
Definition at line 269 of file tractInfo.py.
◆ ctr_coord
|
static |
Definition at line 277 of file tractInfo.py.
◆ inner_sky_polygon
|
static |
Definition at line 357 of file tractInfo.py.
◆ num_patches
|
static |
Definition at line 296 of file tractInfo.py.
◆ outer_sky_polygon
|
static |
Definition at line 364 of file tractInfo.py.
◆ patch_border
|
static |
Definition at line 301 of file tractInfo.py.
◆ patch_inner_dimensions
|
static |
Definition at line 330 of file tractInfo.py.
◆ tract_id
|
static |
Definition at line 284 of file tractInfo.py.
◆ tract_overlap
|
static |
Definition at line 337 of file tractInfo.py.
◆ vertex_list
|
static |
Definition at line 349 of file tractInfo.py.
◆ wcs
|
static |
Definition at line 376 of file tractInfo.py.
The documentation for this class was generated from the following file:
- /j/snowflake/release/lsstsw/stack/lsst-scipipe-8.0.0/Linux64/skymap/ga8c6da7877+a2b54eae19/python/lsst/skymap/tractInfo.py
