lsst.skymap.detail.utils Namespace Reference

class  Index2D

Functions

def coordFromVec (vec, defRA=None)

def makeSkyPolygonFromBBox (bbox, wcs)

◆ coordFromVec()

 def lsst.skymap.detail.utils.coordFromVec ( vec, defRA = None )
Convert an ICRS cartesian vector to an ICRS lsst.geom.SpherePoint

Parameters
----------
vec : list of float
An ICRS catesian vector.
defRA : lsst.geom.Angle or None
The RA to use if the vector is too near a pole;
ignored if not near a pole.

Raises
------
RuntimeError
If vec too near a pole and defRA is None.


Definition at line 34 of file utils.py.

34 def coordFromVec(vec, defRA=None):
35  """Convert an ICRS cartesian vector to an ICRS lsst.geom.SpherePoint
36
37  Parameters
38  ----------
39  vec : list of float
40  An ICRS catesian vector.
41  defRA : lsst.geom.Angle or None
42  The RA to use if the vector is too near a pole;
43  ignored if not near a pole.
44
45  Raises
46  ------
47  RuntimeError
48  If vec too near a pole and defRA is None.
49  """
50  if abs(vec[0]) < _TinyFloat and abs(vec[1]) < _TinyFloat:
51  if defRA is None:
52  raise RuntimeError("At pole and defRA==None")
53  if vec[2] > 0:
54  decDeg = 90.0
55  else:
56  decDeg = -90.0
57  return geom.SpherePoint(defRA, decDeg*geom.degrees)
59
60
Point in an unspecified spherical coordinate system.
Definition: SpherePoint.h:57
Vector3d is a vector in ℝ³ with components stored in double precision.
Definition: Vector3d.h:44
def coordFromVec(vec, defRA=None)
Definition: utils.py:34
Angle abs(Angle const &a)
Definition: Angle.h:106

◆ makeSkyPolygonFromBBox()

 def lsst.skymap.detail.utils.makeSkyPolygonFromBBox ( bbox, wcs )
Make an on-sky polygon from a bbox and a SkyWcs

Parameters
----------
bbox : lsst.geom.Box2I or lsst.geom.Box2D
Bounding box of region, in pixel coordinates
wcs : lsst.afw.geom.SkyWcs
Celestial WCS

Returns
-------
polygon : lsst.sphgeom.ConvexPolygon
On-sky region


Definition at line 61 of file utils.py.

61 def makeSkyPolygonFromBBox(bbox, wcs):
62  """Make an on-sky polygon from a bbox and a SkyWcs
63
64  Parameters
65  ----------
66  bbox : lsst.geom.Box2I or lsst.geom.Box2D
67  Bounding box of region, in pixel coordinates
68  wcs : lsst.afw.geom.SkyWcs
69  Celestial WCS
70
71  Returns
72  -------
73  polygon : lsst.sphgeom.ConvexPolygon
74  On-sky region
75  """
76  pixelPoints = geom.Box2D(bbox).getCorners()
77  skyPoints = wcs.pixelToSky(pixelPoints)
78  return lsst.sphgeom.ConvexPolygon([sp.getVector() for sp in skyPoints])
79
80
A floating-point coordinate rectangle geometry.
Definition: Box.h:413
ConvexPolygon is a closed convex polygon on the unit sphere.
Definition: ConvexPolygon.h:57
def makeSkyPolygonFromBBox(bbox, wcs)
Definition: utils.py:61