lsst.meas.astrom.astrometry Namespace Reference

Classes
class	AstrometryConfig
class	AstrometryTask
	Match an input source catalog with objects from a reference catalog and solve for the WCS. More...

Functions
def	showAstrometry

Function Documentation

def lsst.meas.astrom.astrometry.showAstrometry	(		refCat,
			sourceCat,
			bbox = None,
			exposure = None,
			matches = None,
			frame = 1,
			title = ""
	)

Show an astrometry debug image

@param[in] refCat  reference object catalog; must have fields "centroid_x" and "centroid_y"
@param[in] sourceCat  source catalog; must have field "slot_Centroid_x" and "slot_Centroid_y"
@param[in] exposure  exposure to display, or None for a blank exposure
@param[in] bbox  bounding box of exposure; required if exposure is None and ignored otherwise
@param[in] matches  list of matches (an lsst.afw.table.ReferenceMatchVector), or None
@param[in] frame  frame number for ds9 display
@param[in] title  title for ds9 display

@throw RuntimeError if exposure and bbox are both None

Definition at line 345 of file astrometry.py.

def showAstrometry(refCat, sourceCat, bbox=None, exposure=None, matches=None, frame=1, title=""):
    """Show an astrometry debug image

    @param[in] refCat  reference object catalog; must have fields "centroid_x" and "centroid_y"
    @param[in] sourceCat  source catalog; must have field "slot_Centroid_x" and "slot_Centroid_y"
    @param[in] exposure  exposure to display, or None for a blank exposure
    @param[in] bbox  bounding box of exposure; required if exposure is None and ignored otherwise
    @param[in] matches  list of matches (an lsst.afw.table.ReferenceMatchVector), or None
    @param[in] frame  frame number for ds9 display
    @param[in] title  title for ds9 display

    @throw RuntimeError if exposure and bbox are both None
    """
    import lsst.afw.display.ds9 as ds9

    if exposure is None:
        if bbox is None:
            raise RuntimeError("must specify exposure or bbox")
        exposure = ExposureF(bbox)
    ds9.mtv(exposure, frame=frame, title=title)

    with ds9.Buffering():
        refCentroidKey = Point2DKey(refCat.schema["centroid"])
        for refObj in refCat:
            x, y = refObj.get(refCentroidKey)
            ds9.dot("x", x, y, size=10, frame=frame, ctype=ds9.RED)

        sourceCentroidKey = Point2DKey(sourceCat.schema["slot_Centroid"])
        for source in sourceCat:
            x, y = source.get(sourceCentroidKey)
            ds9.dot("+", x,  y, size=10, frame=frame, ctype=ds9.GREEN)

        if matches:
            radArr = numpy.ndarray(len(matches))

            for i, m in enumerate(matches):
                refCentroid = m.first.get(refCentroidKey)
                sourceCentroid = m.second.get(sourceCentroidKey)
                radArr[i] = math.hypot(*(refCentroid - sourceCentroid))
                ds9.dot("o", x,  y, size=10, frame=frame, ctype=ds9.YELLOW)
                
            print("<match radius> = %.4g +- %.4g [%d matches]" %
                (radArr.mean(), radArr.std(), len(matches)))