lsst.skymap  17.0.1-2-g18434ef+11
wcsFactory.py
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2 # LSST Data Management System
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22 
23 __all__ = ['WcsFactory']
24 
25 import lsst.afw.geom as afwGeom
26 
27 
28 class WcsFactory:
29  """A factory for creating Wcs objects for the sky tiles.
30 
31  Parameters
32  ----------
33  pixelScale : `lsst.geom.Angle`
34  Desired scale, as sky/pixel.
35  projection : `str`
36  FITS-standard 3-letter name of projection, e.g.: TAN (tangent),
37  STG (stereographic), MOL (Mollweide's), AIT (Hammer-Aitoff)
38  see Representations of celestial coordinates in FITS
39  (Calabretta and Greisen, 2002).
40  rotation : `lsst.geom.Angle`
41  Rotation relative to cardinal.
42  flipX : `bool`
43  Flip the X axis?
44  """
45 
46  def __init__(self, pixelScale, projection, rotation=0*afwGeom.radians, flipX=False):
47  if len(projection) != 3:
48  raise RuntimeError("projection=%r; must have length 3" % (projection,))
49  self._projection = projection
50  self._cdMatrix = afwGeom.makeCdMatrix(scale=pixelScale, orientation=rotation, flipX=flipX)
51 
52  def makeWcs(self, crPixPos, crValCoord):
53  """Make a Wcs.
54 
55  Parameters
56  ----------
57  crPixPos : `lsst.geom.Point2D`
58  crPix for WCS, using the LSST standard.
59  crValCoord : `lsst.geom.SpherePoint`
60  ICRS crVal for WCS.
61 
62  Returns
63  -------
64  results : `lsst.afw.geom.SkyWcs`
65  The new SkyWcs object.
66  """
67  return afwGeom.makeSkyWcs(crpix=crPixPos, crval=crValCoord,
68  cdMatrix=self._cdMatrix, projection=self._projection)
def makeWcs(self, crPixPos, crValCoord)
Definition: wcsFactory.py:52
def __init__(self, pixelScale, projection, rotation=0 *afwGeom.radians, flipX=False)
Definition: wcsFactory.py:46