The implementantion in sql of TRACLUS algorithm. More...

Functions
pointsp	projectionpointtraclus (pointsp point, segmentsp segment)
	The function returns the perpendicular projection of point onto a line and is need it by the TRACLUS algorithm. It`s definition is given by [lee2007trajectory.] More...

float8	perpendiculardistancetraclus (segmentsp segmenta, segmentsp segmentb)
	The function returns the perpendicular distance between two segments and is need it by the TRACLUS algorithm. It`s definition is given by [lee2007trajectory.] More...

float8	paralleldistancetraclus (segmentsp segmenta, segmentsp segmentb)
	The function returns the parallel distance between two segments and is need it by the TRACLUS algorithm. It`s definition is given by [lee2007trajectory.] More...

float8	angledistancetraclus (segmentsp segmenta, segmentsp segmentb)
	The function returns the anle distance between two segments and is need it by the TRACLUS algorithm. It`s definition is given by [lee2007trajectory.] More...

float8	traclusdistance (segmentsp segmenta, segmentsp segmentb, real w_perpendicular=1, real w_parallel=1, real w_angle=1)
	The function returns the TRACLUS clustering. It`s definition is given by [lee2007trajectory.] More...

Detailed Description

The implementantion in sql of TRACLUS algorithm.

Author: Marios Vodas (mvoda.nosp@m.s@gm.nosp@m.ail.c.nosp@m.om).

TRACLUS (TRAjectory CLUStering) is an algorithm introduced by [lee2007trajectory] for the trejectoring clustering of similiar trajectories. For more detailed descritpion look at TRACLUS distance functions

See also: TRACLUS distance functions; http://hanj.cs.illinois.edu/pdf/sigmod07_jglee.pdf

Function Documentation

float8 angledistancetraclus	(	segmentsp	segmenta,
		segmentsp	segmentb
	)

The function returns the anle distance between two segments and is need it by the TRACLUS algorithm. It`s definition is given by [lee2007trajectory.]

Parameters

[in]	segmentA	The first segment
[in]	segmentB	The second segment

Returns: angle distance

float8 paralleldistancetraclus	(	segmentsp	segmenta,
		segmentsp	segmentb
	)

The function returns the parallel distance between two segments and is need it by the TRACLUS algorithm. It`s definition is given by [lee2007trajectory.]

Parameters

[in]	segmentA	The first segment
[in]	segmentB	The second segment

Returns: parallel distance

float8 perpendiculardistancetraclus	(	segmentsp	segmenta,
		segmentsp	segmentb
	)

The function returns the perpendicular distance between two segments and is need it by the TRACLUS algorithm. It`s definition is given by [lee2007trajectory.]

Parameters

[in]	segmentA	The first segment
[in]	segmentB	The second segment

Returns: perpendicular distance

pointsp projectionpointtraclus	(	pointsp	point,
		segmentsp	segment
	)

The function returns the perpendicular projection of point onto a line and is need it by the TRACLUS algorithm. It`s definition is given by [lee2007trajectory.]

Parameters

[in]	point	the point for which we are searching the perpendicular distance
[in]	segment	the segment from which we are searching the perpendicular distance

Returns: the point of perpendicular projection of point onto line

float8 traclusdistance	(	segmentsp	segmenta,
		segmentsp	segmentb,
		real	w_perpendicular = `1`,
		real	w_parallel = `1`,
		real	w_angle = `1`
	)

The function returns the TRACLUS clustering. It`s definition is given by [lee2007trajectory.]

Parameters

[in]	segmentA	The first segment
[in]	segmentB	The second segment
[in]	w_perpendicular	I have no idea. Ask marios
[in]	w_parallel	I have no idea
[in]	w_angle	I have no idea

Returns: TRACLUS clustering

Functions

Detailed Description

Function Documentation