Public Member Functions
	__init__ (self, str pixelization, int pix_level, int pix_max_ranges)

list[int]	pixels (self, sphgeom.Region region)

int	pixel (self, sphgeom.UnitVector3d direction)

sphgeom.Region	region (self, int pixel)

list[tuple[int, int]]	envelope (self, sphgeom.Region region)

Public Attributes
	pixelator = sphgeom.HtmPixelization(pix_level)

Protected Attributes
int	_pix_max_ranges = pix_max_ranges

bool	_is_healpix = False

Detailed Description

Wrapper for pixelization classes from `sphgeom` with configurable
pixelization type and parameters.

Parameters
----------
pixelization : `str`
    Name of a pixelization type, one of ""htm", "q3c", "mq3c", or
    "healpix".
pix_level : `int`
    Pixelization level.
pix_max_ranges : `int`
    Maximum number of ranges returned from `envelope()` method.

Definition at line 33 of file pixelization.py.

Constructor & Destructor Documentation

◆ init()

lsst.dax.apdb.pixelization.Pixelization.__init__	(		self,
		str	pixelization,
		int	pix_level,
		int	pix_max_ranges )

Definition at line 48 of file pixelization.py.

    def __init__(self, pixelization: str, pix_level: int, pix_max_ranges: int):
        self._pix_max_ranges = pix_max_ranges
        self._is_healpix = False
 
        if pixelization == "htm":
            self.pixelator = sphgeom.HtmPixelization(pix_level)
        elif pixelization == "q3c":
            self.pixelator = sphgeom.Q3cPixelization(pix_level)
        elif pixelization == "mq3c":
            self.pixelator = sphgeom.Mq3cPixelization(pix_level)
        elif pixelization == "healpix":
            # Healpix does not support maxRanges.
            self._pix_max_ranges = 0
            self._is_healpix = True
            self.pixelator = sphgeom.HealpixPixelization(pix_level)
        else:
            raise ValueError(f"unknown pixelization: {pixelization}")
 

Member Function Documentation

◆ envelope()

list[tuple[int, int]] lsst.dax.apdb.pixelization.Pixelization.envelope	(		self,
		sphgeom.Region	region )

Generate a set of HTM indices covering specified region.

Parameters
----------
region: `sphgeom.Region`
    Region that needs to be indexed.

Returns
-------
ranges : `list` of `tuple`
    Sequence of ranges, range is a tuple (minHtmID, maxHtmID).

Definition at line 107 of file pixelization.py.

    def envelope(self, region: sphgeom.Region) -> list[tuple[int, int]]:
        """Generate a set of HTM indices covering specified region.
 
        Parameters
        ----------
        region: `sphgeom.Region`
            Region that needs to be indexed.
 
        Returns
        -------
        ranges : `list` of `tuple`
            Sequence of ranges, range is a tuple (minHtmID, maxHtmID).
        """
        _LOG.debug("region: %s", region)
        indices = self.pixelator.envelope(region, self._pix_max_ranges)
 
        if _LOG.isEnabledFor(logging.DEBUG):
            for irange in indices.ranges():
                _LOG.debug(
                    "range: %s %s",
                    self.pixelator.toString(irange[0]),
                    self.pixelator.toString(irange[1]),
                )
 
        return indices.ranges()

◆ pixel()

int lsst.dax.apdb.pixelization.Pixelization.pixel	(		self,
		sphgeom.UnitVector3d	direction )

Compute the index of the pixel for given direction.

Parameters
----------
direction : `lsst.sphgeom.UnitVector3d`

Definition at line 81 of file pixelization.py.

    def pixel(self, direction: sphgeom.UnitVector3d) -> int:
        """Compute the index of the pixel for given direction.
 
        Parameters
        ----------
        direction : `lsst.sphgeom.UnitVector3d`
        """
        index = self.pixelator.index(direction)
        return index
 

◆ pixels()

list[int] lsst.dax.apdb.pixelization.Pixelization.pixels	(		self,
		sphgeom.Region	region )

Compute set of the pixel indices for given region.

Parameters
----------
region : `lsst.sphgeom.Region`

Definition at line 66 of file pixelization.py.

    def pixels(self, region: sphgeom.Region) -> list[int]:
        """Compute set of the pixel indices for given region.
 
        Parameters
        ----------
        region : `lsst.sphgeom.Region`
        """
        # We want finest set of pixels, so ask as many pixel as reasonable, but
        # healpix does not support non-zero maxRanges.
        ranges = self.pixelator.envelope(region, 0 if self._is_healpix else 1_000_000)
        indices = []
        for lower, upper in ranges:
            indices += list(range(lower, upper))
        return indices
 

◆ region()

sphgeom.Region lsst.dax.apdb.pixelization.Pixelization.region	(		self,
		int	pixel )

Return region corresponding to a pixel index.

Parameters
----------
pixel : `int`
    Pixel index.

Returns
-------
region : `lsst.sphgeom.Region`
    Region for a given pixel index.

Definition at line 91 of file pixelization.py.

    def region(self, pixel: int) -> sphgeom.Region:
        """Return region corresponding to a pixel index.
 
        Parameters
        ----------
        pixel : `int`
            Pixel index.
 
        Returns
        -------
        region : `lsst.sphgeom.Region`
            Region for a given pixel index.
        """
        region = self.pixelator.pixel(pixel)
        return region
 

Member Data Documentation

◆ _is_healpix

bool lsst.dax.apdb.pixelization.Pixelization._is_healpix = False

protected

Definition at line 50 of file pixelization.py.

◆ _pix_max_ranges

int lsst.dax.apdb.pixelization.Pixelization._pix_max_ranges = pix_max_ranges

protected

Definition at line 49 of file pixelization.py.

◆ pixelator

lsst.dax.apdb.pixelization.Pixelization.pixelator = sphgeom.HtmPixelization(pix_level)

Definition at line 53 of file pixelization.py.

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

/j/snowflake/release/lsstsw/stack/lsst-scipipe-12.1.0/Linux/dax_apdb/gb88ae4c679+7dec8f19df/python/lsst/dax/apdb/pixelization.py

Public Member Functions

Public Attributes

Protected Attributes