lsst.geom.geometry.SphericalBox Class Reference

Inheritance diagram for lsst.geom.geometry.SphericalBox:

Public Member Functions
def	__init__
def	wraps
def	getBoundingBox
def	getMin
def	getMax
def	getThetaExtent
def	getCenter
def	isEmpty
def	isFull
def	containsPoint
def	contains
def	intersects
def	extend
def	shrink
def	setEmpty
def	setFull
def	__repr__
def	__eq__

Static Public Member Functions
def	edge

Public Attributes
	min
	max

Detailed Description

A spherical coordinate space bounding box.

This is similar to a bounding box in cartesian space in that
it is specified by a pair of points; however, a spherical box may
correspond to the entire unit-sphere, a spherical cap, a lune or
the traditional rectangle. Additionally, spherical boxes can span
the 0/360 degree longitude angle discontinuity.

Note that points falling exactly on spherical box edges are
considered to be inside (contained by) the box.

Definition at line 347 of file geometry.py.

Constructor & Destructor Documentation

def lsst.geom.geometry.SphericalBox.__init__	(		self,
			args
	)

Creates a new spherical box. If no arguments are supplied, then
an empty box is created. If the arguments consist of a single
SphericalRegion, then a copy of its bounding box is created.
Otherwise, the arguments must consist of a pair of 2 (spherical)
or 3 (cartesian 3-vector) element coordinate tuples/lists that
specify the minimum/maximum longitude/latitude angles for the box.
Latitude angles must be within [-90, 90] degrees, and the minimum
latitude angle must be less than or equal to the maximum. If both
minimum and maximum longitude angles lie in the range [0.0, 360.0],
then the maximum can be less than the minimum. For example, a box
with min/max longitude angles of 350/10 deg spans the longitude angle
ranges [350, 360) and [0, 10]. Otherwise, the minimum must be less
than or equal to the maximum, though values can be arbitrary. If
the two are are separated by 360 degrees or more, then the box
spans longitude angles [0, 360). Otherwise, both values are range
reduced. For example, a spherical box with min/max longitude angles
specified as 350/370 deg spans longitude angle ranges [350, 360) and
[0, 10].

Definition at line 359 of file geometry.py.

    def __init__(self, *args):
        """
        Creates a new spherical box. If no arguments are supplied, then
        an empty box is created. If the arguments consist of a single
        SphericalRegion, then a copy of its bounding box is created.
        Otherwise, the arguments must consist of a pair of 2 (spherical)
        or 3 (cartesian 3-vector) element coordinate tuples/lists that
        specify the minimum/maximum longitude/latitude angles for the box.
        Latitude angles must be within [-90, 90] degrees, and the minimum
        latitude angle must be less than or equal to the maximum. If both
        minimum and maximum longitude angles lie in the range [0.0, 360.0],
        then the maximum can be less than the minimum. For example, a box
        with min/max longitude angles of 350/10 deg spans the longitude angle
        ranges [350, 360) and [0, 10]. Otherwise, the minimum must be less
        than or equal to the maximum, though values can be arbitrary. If
        the two are are separated by 360 degrees or more, then the box
        spans longitude angles [0, 360). Otherwise, both values are range
        reduced. For example, a spherical box with min/max longitude angles
        specified as 350/370 deg spans longitude angle ranges [350, 360) and
        [0, 10].
        """
        if len(args) == 0:
            self.setEmpty()
            return
        elif len(args) == 1:
            if isinstance(args[0], SphericalRegion):
                bbox = args[0].getBoundingBox()
                self.min = tuple(bbox.getMin())
                self.max = tuple(bbox.getMax())
                return
            args = args[0]
        if len(args) == 2:
            self.min = sphericalCoords(args[0])
            self.max = sphericalCoords(args[1])
        else:
            raise TypeError('Expecting a spherical region, 2 points, '
                            'or a tuple/list containing 2 points')
        if self.min[1] > self.max[1]:
            raise RuntimeError(
                'Latitude angle minimum is greater than maximum')
        if (self.max[0] < self.min[0] and
            (self.max[0] < 0.0 or self.min[0] > 360.0)):
            raise RuntimeError(
                'Longitude angle minimum is greater than maximum')
        # Range-reduce longitude angles
        if self.max[0] - self.min[0] >= 360.0:
            self.min = (0.0, self.min[1])
            self.max = (360.0, self.max[1])
        else:
            self.min = (reduceTheta(self.min[0]), self.min[1])
            self.max = (reduceTheta(self.max[0]), self.max[1])