lsst.skymap  14.0-5-g3f35923+2
utils.py
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1 #
2 # LSST Data Management System
3 # Copyright 2008, 2009, 2010 LSST Corporation.
4 #
5 # This product includes software developed by the
6 # LSST Project (http://www.lsst.org/).
7 #
8 # This program is free software: you can redistribute it and/or modify
9 # it under the terms of the GNU General Public License as published by
10 # the Free Software Foundation, either version 3 of the License, or
11 # (at your option) any later version.
12 #
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
17 #
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20 # see <http://www.lsstcorp.org/LegalNotices/>.
21 #
22 import numpy
23 
24 import lsst.afw.geom as afwGeom
25 
26 __all__ = ["coordFromVec"]
27 
28 _TinyFloat = numpy.finfo(float).tiny
29 
30 
31 def coordFromVec(vec, defRA=None):
32  """Convert an ICRS cartesian vector to an ICRS lsst.afw.geom.SpherePoint
33 
34  @param[in] vec: an ICRS catesian vector as a sequence of three floats
35  @param[in] defRA: the RA to use if the vector is too near a pole (an afwGeom Angle);
36  ignored if not near a pole
37 
38  @throw RuntimeError if vec too near a pole and defRA is None
39  """
40  if abs(vec[0]) < _TinyFloat and abs(vec[1]) < _TinyFloat:
41  if defRA is None:
42  raise RuntimeError("At pole and defRA==None")
43  if vec[2] > 0:
44  decDeg = 90.0
45  else:
46  decDeg = -90.0
47  return afwGeom.SpherePoint(defRA, decDeg*afwGeom.degrees)
48  return afwGeom.SpherePoint(afwGeom.Point3D(*vec))
def coordFromVec(vec, defRA=None)
Definition: utils.py:31