LSST Applications  21.0.0+c4f5df5339,21.0.0+e70536a077,21.0.0-1-ga51b5d4+7c60f8a6ea,21.0.0-10-g560fb7b+411cd868f8,21.0.0-10-gcf60f90+8c49d86aa0,21.0.0-13-gc485e61d+38156233bf,21.0.0-16-g7a993c7b9+1041c3824f,21.0.0-2-g103fe59+d9ceee3e5a,21.0.0-2-g1367e85+0b2f7db15a,21.0.0-2-g45278ab+e70536a077,21.0.0-2-g5242d73+0b2f7db15a,21.0.0-2-g7f82c8f+feb9862f5e,21.0.0-2-g8f08a60+9c9a9cfcc8,21.0.0-2-ga326454+feb9862f5e,21.0.0-2-gde069b7+bedfc5e1fb,21.0.0-2-gecfae73+417509110f,21.0.0-2-gfc62afb+0b2f7db15a,21.0.0-3-g21c7a62+a91f7c0b59,21.0.0-3-g357aad2+062581ff1a,21.0.0-3-g4be5c26+0b2f7db15a,21.0.0-3-g65f322c+85aa0ead76,21.0.0-3-g7d9da8d+c4f5df5339,21.0.0-3-gaa929c8+411cd868f8,21.0.0-3-gc44e71e+fd4029fd48,21.0.0-3-ge02ed75+5d9b90b8aa,21.0.0-38-g070523fc+44fda2b515,21.0.0-4-g591bb35+5d9b90b8aa,21.0.0-4-g88306b8+3cdc83ea97,21.0.0-4-gc004bbf+d52368b591,21.0.0-4-gccdca77+a5c54364a0,21.0.0-5-g7ebb681+81e2098694,21.0.0-5-gdf36809+87b8d260e6,21.0.0-6-g2d4f3f3+e70536a077,21.0.0-6-g4e60332+5d9b90b8aa,21.0.0-6-g5ef7dad+3f4e29eeae,21.0.0-7-gc8ca178+0f5e56d48f,21.0.0-9-g9eb8d17+cc2c7a81aa,master-gac4afde19b+5d9b90b8aa,w.2021.07
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 8 of file calculateSipWcsHeader.py.

8 def calculateSipWcsHeader(wcs, order, bbox, spacing, header=None):
9  """Generate a SIP WCS header approximating a given ``SkyWcs``
10 
11  Parameters
12  ----------
13  wcs : `lsst.afw.geom.SkyWcs`
14  World Coordinate System to approximate as SIP.
15  order : `int`
16  SIP order (equal to the maximum sum of the polynomial exponents).
17  bbox : `lsst.geom.Box2I`
18  Bounding box over which to approximate the ``wcs``.
19  spacing : `float`
20  Spacing between sample points.
21  header : `lsst.daf.base.PropertyList`, optional
22  Header to which to add SIP WCS keywords.
23 
24  Returns
25  -------
26  header : `lsst.daf.base.PropertyList`
27  Header including SIP WCS keywords.
28 
29  Examples
30  --------
31  >>> header = calculateSipWcsHeader(exposure.getWcs(), 3, exposure.getBBox(), 20)
32  >>> sipWcs = SkyWcs(header)
33  """
34  transform = getPixelToIntermediateWorldCoords(wcs)
35  crpix = wcs.getPixelOrigin()
36  cdMatrix = wcs.getCdMatrix()
37  crval = wcs.getSkyOrigin()
38  gridNum = Extent2I(int(bbox.getWidth()/spacing + 0.5), int(bbox.getHeight()/spacing + 0.5))
39 
40  sip = SipApproximation(transform, crpix, cdMatrix, Box2D(bbox), gridNum, order)
41 
42  md = makeTanSipMetadata(sip.getPixelOrigin(), crval, sip.getCdMatrix(), sip.getA(), sip.getB(),
43  sip.getAP(), sip.getBP())
44 
45  if header is not None:
46  header.combine(md)
47  else:
48  header = md
49 
50  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:564
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:197
Extent< int, 2 > Extent2I
Definition: Extent.h:397