lsst.skymap g037fbe16b5+d85c0663ba
utils.py
Go to the documentation of this file.
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#
18# You should have received a copy of the LSST License Statement and
19# the GNU General Public License along with this program. If not,
20# see <http://www.lsstcorp.org/LegalNotices/>.
21#
22
23__all__ = ["coordFromVec"]
24
25import numpy
26
27import lsst.sphgeom
28import lsst.geom as geom
29
30
31_TinyFloat = numpy.finfo(float).tiny
32
33
34def 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)
def coordFromVec(vec, defRA=None)
Definition: utils.py:34