lsst.pipe.tasks.reserveIsolatedStars.ReserveIsolatedStarsTask Class Reference

Inheritance diagram for lsst.pipe.tasks.reserveIsolatedStars.ReserveIsolatedStarsTask:

Public Member Functions
	run (self, nstar, extra='')

Static Public Attributes
	ConfigClass = ReserveIsolatedStarsConfig

Static Protected Attributes
str	_DefaultName = 'reserve_isolated_stars'

Detailed Description

Reserve isolated stars with repeatable hash.

Definition at line 53 of file reserveIsolatedStars.py.

Member Function Documentation

run()

lsst.pipe.tasks.reserveIsolatedStars.ReserveIsolatedStarsTask.run	(		self,
			nstar,
			extra = '' )

Retrieve a selection of reserved stars.

Parameters
----------
nstar : `int`
    Number of stars to select from.
extra : `str`, optional
    Extra name to appended to reserve_name, often tract or pixel,
    and may be combined with band name.

Returns
-------
selection : `np.ndarray` (N,)
    Boolean index array, with ``True`` for reserved stars.

Definition at line 58 of file reserveIsolatedStars.py.

    def run(self, nstar, extra=''):
        """Retrieve a selection of reserved stars.
 
        Parameters
        ----------
        nstar : `int`
            Number of stars to select from.
        extra : `str`, optional
            Extra name to appended to reserve_name, often tract or pixel,
            and may be combined with band name.
 
        Returns
        -------
        selection : `np.ndarray` (N,)
            Boolean index array, with ``True`` for reserved stars.
        """
        selection = np.zeros(nstar, dtype=bool)
 
        if self.config.reserve_fraction == 0.0:
            return selection
 
        # Full name combines the configured reserve name and the tract.
        name = self.config.reserve_name + '_' + extra
        # Random seed is the lower 32 bits of the hashed name.
        # We use hashlib.sha256 for guaranteed repeatability.
        hex_hash = hashlib.sha256(name.encode('UTF-8')).hexdigest()
        seed = int('0x' + hex_hash, 0) & 0xFFFFFFFF
 
        rng = np.random.default_rng(seed)
 
        selection[:int(nstar*self.config.reserve_fraction)] = True
        rng.shuffle(selection)
 
        return selection

Member Data Documentation

_DefaultName

str lsst.pipe.tasks.reserveIsolatedStars.ReserveIsolatedStarsTask._DefaultName = 'reserve_isolated_stars'

staticprotected

Definition at line 56 of file reserveIsolatedStars.py.

ConfigClass

lsst.pipe.tasks.reserveIsolatedStars.ReserveIsolatedStarsTask.ConfigClass = ReserveIsolatedStarsConfig

static

Definition at line 55 of file reserveIsolatedStars.py.

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

• /j/snowflake/release/lsstsw/stack/lsst-scipipe-8.0.0/Linux64/pipe_tasks/gc07e1c2157+a98bf949bb/python/lsst/pipe/tasks/reserveIsolatedStars.py