Public Member Functions
	__init__ (self, inputSkyWcs)

	makeWcs (self, linearShift, affMatrix)

Public Attributes
	frameDict

	frameIdxs

	frameMin

	frameMax

	mapFrom

	mapTo

	lastMapBeforeSky

	origin

Detailed Description

Convenience class for appending a shifting an input SkyWcs on sky and
appending an affine transform.

The class assumes that all frames are sequential and are mapped one to the
next.

Parameters
----------
input_sky_wcs : `lsst.afw.geom.SkyWcs`
    WCS to decompose and append affine matrix and shift in on sky
    location to.

Definition at line 209 of file fitAffineWcs.py.

Constructor & Destructor Documentation

◆ init()

lsst.meas.astrom.fitAffineWcs.TransformedSkyWcsMaker.__init__	(		self,
			inputSkyWcs )

Definition at line 223 of file fitAffineWcs.py.

    def __init__(self, inputSkyWcs):
        self.frameDict = inputSkyWcs.getFrameDict()
 
        # Grab the order of the frames by index.
        # TODO: DM-20825
        #    Change the frame the transform is appended to to be explicitly
        #    the FIELD_ANGLE->IWC transform. Requires related tickets to be
        #    completed.
        domains = self.frameDict.getAllDomains()
        self.frameIdxs = np.sort([self.frameDict.getIndex(domain)
                                  for domain in domains])
        self.frameMin = np.min(self.frameIdxs)
        self.frameMax = np.max(self.frameIdxs)
 
        # Find frame just before the final mapping to sky and store those
        # indices and mappings for later.
        self.mapFrom = self.frameMax - 2
        if self.mapFrom < self.frameMin:
            self.mapFrom = self.frameMin
        self.mapTo = self.frameMax - 1
        if self.mapTo <= self.mapFrom:
            self.mapTo = self.frameMax
        self.lastMapBeforeSky = self.frameDict.getMapping(
            self.mapFrom, self.mapTo)
 
        # Get the original WCS sky location.
 
        self.origin = inputSkyWcs.getSkyOrigin()
 

Member Function Documentation

◆ makeWcs()

lsst.meas.astrom.fitAffineWcs.TransformedSkyWcsMaker.makeWcs	(	self,
		linearShift,
		affMatrix )

Apply a shift and affine transform to the WCS internal to this
class.

A new SkyWcs with these transforms applied is returns.

Parameters
----------
linearShift : `numpy.ndarray`, (2,)
    A linear shift to apply at the same time as applying the affine
    matrix transform.
aff_matrix : 'numpy.ndarray', (3, 3)
    Affine matrix to apply to the mapping/transform to add to the
    WCS.

Returns
-------
outputWcs : `lsst.afw.geom.SkyWcs`
    Wcs with a final shift and affine transform applied.

Definition at line 252 of file fitAffineWcs.py.

    def makeWcs(self, linearShift, affMatrix):
        """Apply a shift and affine transform to the WCS internal to this
        class.
 
        A new SkyWcs with these transforms applied is returns.
 
        Parameters
        ----------
        linearShift : `numpy.ndarray`, (2,)
            A linear shift to apply at the same time as applying the affine
            matrix transform.
        aff_matrix : 'numpy.ndarray', (3, 3)
            Affine matrix to apply to the mapping/transform to add to the
            WCS.
 
        Returns
        -------
        outputWcs : `lsst.afw.geom.SkyWcs`
            Wcs with a final shift and affine transform applied.
        """
        # Create a WCS that only maps from IWC to Sky with the shifted
        # Sky origin position. This is simply the final undistorted tangent
        # plane to sky. The PIXELS to SKY map will be become our IWC to SKY
        # map and gives us our final shift position.
        iwcsToSkyWcs = makeSkyWcs(
            Point2D(0., 0.),
            self.origin,
            np.array([[1., 0.], [0., 1.]]))
        iwcToSkyMap = iwcsToSkyWcs.getFrameDict().getMapping("PIXELS", "SKY")
 
        # Append a simple affine Matrix transform to the current to the
        # second to last frame mapping. e.g. the one just before IWC to SKY.
        newMapping = self.lastMapBeforeSky.then(astshim.MatrixMap(affMatrix))
        newMapping = newMapping.then(astshim.ShiftMap(linearShift))
 
        # Create a new frame dict starting from the input_sky_wcs's first
        # frame. Append the correct mapping created above and our new on
        # sky location.
        outputFrameDict = astshim.FrameDict(
            self.frameDict.getFrame(self.frameMin))
        for frameIdx in self.frameIdxs:
            if frameIdx == self.mapFrom:
                outputFrameDict.addFrame(
                    self.mapFrom,
                    newMapping,
                    self.frameDict.getFrame(self.mapTo))
            elif frameIdx >= self.mapTo:
                continue
            else:
                outputFrameDict.addFrame(
                    frameIdx,
                    self.frameDict.getMapping(frameIdx, frameIdx + 1),
                    self.frameDict.getFrame(frameIdx + 1))
        # Append the final sky frame to the frame dict.
        outputFrameDict.addFrame(
            self.frameMax - 1,
            iwcToSkyMap,
            iwcsToSkyWcs.getFrameDict().getFrame("SKY"))
 
        return SkyWcs(outputFrameDict)

Member Data Documentation

◆ frameDict

lsst.meas.astrom.fitAffineWcs.TransformedSkyWcsMaker.frameDict

Definition at line 224 of file fitAffineWcs.py.

◆ frameIdxs

lsst.meas.astrom.fitAffineWcs.TransformedSkyWcsMaker.frameIdxs

Definition at line 232 of file fitAffineWcs.py.

◆ frameMax

lsst.meas.astrom.fitAffineWcs.TransformedSkyWcsMaker.frameMax

Definition at line 235 of file fitAffineWcs.py.

◆ frameMin

lsst.meas.astrom.fitAffineWcs.TransformedSkyWcsMaker.frameMin

Definition at line 234 of file fitAffineWcs.py.

◆ lastMapBeforeSky

lsst.meas.astrom.fitAffineWcs.TransformedSkyWcsMaker.lastMapBeforeSky

Definition at line 245 of file fitAffineWcs.py.

◆ mapFrom

lsst.meas.astrom.fitAffineWcs.TransformedSkyWcsMaker.mapFrom

Definition at line 239 of file fitAffineWcs.py.

◆ mapTo

lsst.meas.astrom.fitAffineWcs.TransformedSkyWcsMaker.mapTo

Definition at line 242 of file fitAffineWcs.py.

◆ origin

lsst.meas.astrom.fitAffineWcs.TransformedSkyWcsMaker.origin

Definition at line 250 of file fitAffineWcs.py.

The documentation for this class was generated from the following file:

/j/snowflake/release/lsstsw/stack/lsst-scipipe-8.0.0/Linux64/meas_astrom/gf1cff7945b+21ad69e7e1/python/lsst/meas/astrom/fitAffineWcs.py

Public Member Functions

Public Attributes