lsst.meas.algorithms.pcaPsfDeterminer Namespace Reference

Classes
class	PcaPsfDeterminerConfig
class	PcaPsfDeterminerTask

Functions
def	numCandidatesToReject (numBadCandidates, numIter, totalIter)
def	candidatesIter (psfCellSet, ignoreBad=True)

Function Documentation

candidatesIter()

def lsst.meas.algorithms.pcaPsfDeterminer.candidatesIter	(		psfCellSet,
			ignoreBad = True
	)

Generator for Psf candidates.

This allows two 'for' loops to be reduced to one.

Parameters
----------
psfCellSet : `lsst.afw.math.SpatialCellSet`
   SpatialCellSet of PSF candidates.
ignoreBad : `bool`, optional
   Ignore candidates flagged as BAD?

Yields
-------
cell : `lsst.afw.math.SpatialCell`
   A SpatialCell.
cand : `lsst.meas.algorithms.PsfCandidate`
  A PsfCandidate.

Definition at line 651 of file pcaPsfDeterminer.py.

def candidatesIter(psfCellSet, ignoreBad=True):
    """Generator for Psf candidates.
 
    This allows two 'for' loops to be reduced to one.
 
    Parameters
    ----------
    psfCellSet : `lsst.afw.math.SpatialCellSet`
       SpatialCellSet of PSF candidates.
    ignoreBad : `bool`, optional
       Ignore candidates flagged as BAD?
 
    Yields
    -------
    cell : `lsst.afw.math.SpatialCell`
       A SpatialCell.
    cand : `lsst.meas.algorithms.PsfCandidate`
      A PsfCandidate.
    """
    for cell in psfCellSet.getCellList():
        for cand in cell.begin(ignoreBad):
            yield (cell, cand)
 
 
psfDeterminerRegistry.register("pca", PcaPsfDeterminerTask)

numCandidatesToReject()

def lsst.meas.algorithms.pcaPsfDeterminer.numCandidatesToReject	(		numBadCandidates,
			numIter,
			totalIter
	)

Return the number of PSF candidates to be rejected.

The number of candidates being rejected on each iteration gradually
increases, so that on the Nth of M iterations we reject N/M of the bad
candidates.

Parameters
----------
numBadCandidates : `int`
    Number of bad candidates under consideration.

numIter : `int`
    The number of the current PSF iteration.

totalIter : `int`
    The total number of PSF iterations.

Returns
-------
return : `int`
    Number of candidates to reject.

Definition at line 44 of file pcaPsfDeterminer.py.

def numCandidatesToReject(numBadCandidates, numIter, totalIter):
    """Return the number of PSF candidates to be rejected.
 
    The number of candidates being rejected on each iteration gradually
    increases, so that on the Nth of M iterations we reject N/M of the bad
    candidates.
 
    Parameters
    ----------
    numBadCandidates : `int`
        Number of bad candidates under consideration.
 
    numIter : `int`
        The number of the current PSF iteration.
 
    totalIter : `int`
        The total number of PSF iterations.
 
    Returns
    -------
    return : `int`
        Number of candidates to reject.
    """
    return int(numBadCandidates*(numIter + 1)//totalIter + 0.5)