SpatialIndex Class Reference

#include <SpatialIndex.h>

Collaboration diagram for SpatialIndex:

Classes
struct	Layer
struct	QuadNode
Public Member Functions
size_t	getMaxlevel ()
size_t	getBildLevel ()
	SpatialIndex ()
	SpatialIndex (size_t maxlevel, size_t buildlevel=5)
uint32	leafNumberById (uint64 ID) const
uint64	idByLeafNumber (uint32 n) const
char *	nameByLeafNumber (uint32 n, char *name=0) const
void	pointById (SpatialVector &vector, uint64 ID) const
uint64	idByPoint (SpatialVector &vector) const
uint64	idByPoint (const float64 &ra, const float64 &dec) const
	find a node by giving a ra,dec in degrees.
char *	nameByPoint (SpatialVector &vector, char *s=NULL) const
	find a node by giving a vector.
char *	nameByPoint (const float64 &ra, const float64 &dec, char *s=NULL) const
	find a node by giving a ra,dec in degrees.
uint64	leafCount () const
	return number of leaf nodes
size_t	nVertices () const
	return number of vertices
float64	area (uint64 ID) const
	The area in steradians for a given index ID.
float64	area (const SpatialVector &v1, const SpatialVector &v2, const SpatialVector &v3) const
	The area in steradians for a given spatial triangle.
void	nodeVertex (const uint64 id, SpatialVector &v1, SpatialVector &v2, SpatialVector &v3) const
	return the actual vertex vectors
void	nodeVertex (const size_t idx, size_t &v1, size_t &v2, size_t &v3) const
	return index of vertices for a node
void	showVertices (ostream &out) const
	print all vertices to output stream
void	setMaxlevel (int level)
	set the maximum depth of the layer
Static Public Member Functions
static uint64	idByName (const char *)
	NodeName conversion to integer ID.
static char *	nameById (uint64 ID, char *name=0)
Private Types
typedef std::vector< QuadNode >	ValueVectorQuad
typedef std::vector < SpatialVector >	ValueVectorSpvec
Private Member Functions
uint64	newNode (size_t v1, size_t v2, size_t v3, uint64 id, uint64 parent)
void	makeNewLayer (size_t oldlayer)
void	vMax (size_t nodes, size_t vertices)
void	sortIndex ()
bool	isInside (const SpatialVector &v, const SpatialVector &v0, const SpatialVector &v1, const SpatialVector &v2) const
Private Attributes
size_t	maxlevel_
size_t	buildlevel_
uint64	leaves_
uint64	storedleaves_
ValueVectorQuad	nodes_
std::vector< Layer >	layers_
ValueVectorSpvec	vertices_
uint64	index_
Friends
class	SpatialEdge
class	SpatialConvex
class	RangeConvex
class	SpatialDomain
class	htmInterface

Detailed Description

The Spatial Index is a quad tree of spherical triangles. The tree is built in the following way: Start out with 8 triangles on the sphere using the 3 main circles to determine them. Then, every triangle can be decomposed into 4 new triangles by drawing main circles between midpoints of its edges:

.                            /\
.                           /  \
.                          /____\
.                         /\    /\
.                        /  \  /  \
.                       /____\/____\

This is how the quad tree is built up to a certain level by decomposing every triangle again and again.

Member Typedef Documentation

typedef std::vector<QuadNode> SpatialIndex::ValueVectorQuad [private]

typedef std::vector<SpatialVector> SpatialIndex::ValueVectorSpvec [private]

Constructor & Destructor Documentation

SpatialIndex::SpatialIndex ( ) [inline]

Constructor. Give the level of the index and optionally the level to build - i.e. the depth to keep in memory. if maxlevel - buildlevel > 0 , that many levels are generated on the fly each time the index is called.

SpatialIndex::SpatialIndex	(	size_t	maxlevel,
		size_t	buildlevel = `5`
	)

References buildlevel_, index_, layers_, SpatialEdge::makeMidPoints(), makeNewLayer(), N, newNode(), nodes_, sortIndex(), vertices_, and vMax().

Member Function Documentation

float64 SpatialIndex::area	(	const SpatialVector &	v1,
		const SpatialVector &	v2,
		const SpatialVector &	v3
	)			const

The area in steradians for a given spatial triangle.

References area().

float64 SpatialIndex::area ( uint64 ID ) const

The area in steradians for a given index ID.

References nodeVertex().

Referenced by area().

size_t SpatialIndex::getBildLevel ( ) [inline]

size_t SpatialIndex::getMaxlevel ( ) [inline]

uint64 SpatialIndex::idByLeafNumber ( uint32 n ) const [inline]

Return leaf id for a certain bitlist index. Same as the function above

References leafCount().

Referenced by nameByLeafNumber().

uint64 SpatialIndex::idByName ( const char * name ) [static]

NodeName conversion to integer ID.

References HTMNAMEMAX.

Referenced by idByPoint().

uint64 SpatialIndex::idByPoint	(	const float64 &	ra,
		const float64 &	dec
	)			const `[inline]`

find a node by giving a ra,dec in degrees.

References idByPoint().

uint64 SpatialIndex::idByPoint ( SpatialVector & vector ) const

find a node by giving a vector. The ID of the node is returned.

References buildlevel_, gEpsilon, HTMNAMEMAX, ICHILD, idByName(), isInside(), maxlevel_, N, nameById(), nodes_, SpatialVector::normalize(), pointById(), and V.

Referenced by idByPoint(), and nameByPoint().

bool SpatialIndex::isInside	(	const SpatialVector &	v,
		const SpatialVector &	v0,
		const SpatialVector &	v1,
		const SpatialVector &	v2
	)			const `[private]`

References gEpsilon.

Referenced by idByPoint().

uint64 SpatialIndex::leafCount ( ) const [inline]

return number of leaf nodes

References leaves_.

Referenced by idByLeafNumber(), and leafNumberById().

uint32 SpatialIndex::leafNumberById ( uint64 ID ) const [inline]

Return leaf number in bitlist for a certain ID. Since the ID here means the number computed from the name, this is simply returning ID -leafCount(). Bitlists only work until level 14.

References HTMMAXBIT, leafCount(), and maxlevel_.

void SpatialIndex::makeNewLayer ( size_t oldlayer ) [private]

References ICHILD, index_, IV, IW, layers_, N, and newNode().

Referenced by SpatialIndex().

char * SpatialIndex::nameById	(	uint64	ID,
		char *	name = `0`
	)			`[static]`

int32 conversion to a string (name of database). WARNING: if name is already allocated, a size of at least 17 is required. The conversion is done by directly calculating the name from a number. To calculate the name of a certain level, the mechanism is that the name is given by (of nodes in that level) + (id of node). So for example, for the first level, there are 8 nodes, and we get the names from numbers 8 through 15 giving S0,S1,S2,S3,N0,N1,N2,N3. The order is always ascending starting from S0000.. to N3333...

References IDHIGHBIT, IDHIGHBIT2, and IDSIZE.

Referenced by idByPoint(), nameByLeafNumber(), nameByPoint(), and pointById().