LSST Applications  21.0.0-172-gfb10e10a+18fedfabac,22.0.0+297cba6710,22.0.0+80564b0ff1,22.0.0+8d77f4f51a,22.0.0+a28f4c53b1,22.0.0+dcf3732eb2,22.0.1-1-g7d6de66+2a20fdde0d,22.0.1-1-g8e32f31+297cba6710,22.0.1-1-geca5380+7fa3b7d9b6,22.0.1-12-g44dc1dc+2a20fdde0d,22.0.1-15-g6a90155+515f58c32b,22.0.1-16-g9282f48+790f5f2caa,22.0.1-2-g92698f7+dcf3732eb2,22.0.1-2-ga9b0f51+7fa3b7d9b6,22.0.1-2-gd1925c9+bf4f0e694f,22.0.1-24-g1ad7a390+a9625a72a8,22.0.1-25-g5bf6245+3ad8ecd50b,22.0.1-25-gb120d7b+8b5510f75f,22.0.1-27-g97737f7+2a20fdde0d,22.0.1-32-gf62ce7b1+aa4237961e,22.0.1-4-g0b3f228+2a20fdde0d,22.0.1-4-g243d05b+871c1b8305,22.0.1-4-g3a563be+32dcf1063f,22.0.1-4-g44f2e3d+9e4ab0f4fa,22.0.1-42-gca6935d93+ba5e5ca3eb,22.0.1-5-g15c806e+85460ae5f3,22.0.1-5-g58711c4+611d128589,22.0.1-5-g75bb458+99c117b92f,22.0.1-6-g1c63a23+7fa3b7d9b6,22.0.1-6-g50866e6+84ff5a128b,22.0.1-6-g8d3140d+720564cf76,22.0.1-6-gd805d02+cc5644f571,22.0.1-8-ge5750ce+85460ae5f3,master-g6e05de7fdc+babf819c66,master-g99da0e417a+8d77f4f51a,w.2021.48
LSST Data Management Base Package
Functions
lsst.afw.geom._calculateSipWcsHeader Namespace Reference

Functions

def calculateSipWcsHeader (wcs, order, bbox, spacing, header=None)
 

Function Documentation

◆ calculateSipWcsHeader()

def lsst.afw.geom._calculateSipWcsHeader.calculateSipWcsHeader (   wcs,
  order,
  bbox,
  spacing,
  header = None 
)
Generate a SIP WCS header approximating a given ``SkyWcs``

Parameters
----------
wcs : `lsst.afw.geom.SkyWcs`
    World Coordinate System to approximate as SIP.
order : `int`
    SIP order (equal to the maximum sum of the polynomial exponents).
bbox : `lsst.geom.Box2I`
    Bounding box over which to approximate the ``wcs``.
spacing : `float`
    Spacing between sample points.
header : `lsst.daf.base.PropertyList`, optional
    Header to which to add SIP WCS keywords.

Returns
-------
header : `lsst.daf.base.PropertyList`
    Header including SIP WCS keywords.

Examples
--------
>>> header = calculateSipWcsHeader(exposure.getWcs(), 3, exposure.getBBox(), 20)
>>> sipWcs = SkyWcs(header)

Definition at line 30 of file _calculateSipWcsHeader.py.

30 def calculateSipWcsHeader(wcs, order, bbox, spacing, header=None):
31  """Generate a SIP WCS header approximating a given ``SkyWcs``
32 
33  Parameters
34  ----------
35  wcs : `lsst.afw.geom.SkyWcs`
36  World Coordinate System to approximate as SIP.
37  order : `int`
38  SIP order (equal to the maximum sum of the polynomial exponents).
39  bbox : `lsst.geom.Box2I`
40  Bounding box over which to approximate the ``wcs``.
41  spacing : `float`
42  Spacing between sample points.
43  header : `lsst.daf.base.PropertyList`, optional
44  Header to which to add SIP WCS keywords.
45 
46  Returns
47  -------
48  header : `lsst.daf.base.PropertyList`
49  Header including SIP WCS keywords.
50 
51  Examples
52  --------
53  >>> header = calculateSipWcsHeader(exposure.getWcs(), 3, exposure.getBBox(), 20)
54  >>> sipWcs = SkyWcs(header)
55  """
56  transform = getPixelToIntermediateWorldCoords(wcs)
57  crpix = wcs.getPixelOrigin()
58  cdMatrix = wcs.getCdMatrix()
59  crval = wcs.getSkyOrigin()
60  gridNum = Extent2I(int(bbox.getWidth()/spacing + 0.5), int(bbox.getHeight()/spacing + 0.5))
61 
62  sip = SipApproximation(transform, crpix, cdMatrix, Box2D(bbox), gridNum, order)
63 
64  md = makeTanSipMetadata(sip.getPixelOrigin(), crval, sip.getCdMatrix(), sip.getA(), sip.getB(),
65  sip.getAP(), sip.getBP())
66 
67  if header is not None:
68  header.combine(md)
69  else:
70  header = md
71 
72  return header
def calculateSipWcsHeader(wcs, order, bbox, spacing, header=None)
std::shared_ptr< TransformPoint2ToPoint2 > getPixelToIntermediateWorldCoords(SkyWcs const &wcs, bool simplify=true)
Return a transform from pixel coordinates to intermediate world coordinates.
Definition: SkyWcs.cc:559
std::shared_ptr< daf::base::PropertyList > makeTanSipMetadata(lsst::geom::Point2D const &crpix, lsst::geom::SpherePoint const &crval, Eigen::Matrix2d const &cdMatrix, Eigen::MatrixXd const &sipA, Eigen::MatrixXd const &sipB)
Make metadata for a TAN-SIP WCS without inverse matrices.
Definition: wcsUtils.cc:194
Extent< int, 2 > Extent2I
Definition: Extent.h:397