com.vividsolutions.jts.algorithm
Class RobustDeterminant
java.lang.Object
com.vividsolutions.jts.algorithm.RobustDeterminant
public class RobustDeterminant
- extends java.lang.Object
Implements an algorithm to compute the
sign of a 2x2 determinant for double precision values robustly.
It is a direct translation of code developed by Olivier Devillers.
The original code carries the following copyright notice:
Author : Olivier Devillers
Olivier.Devillers@sophia.inria.fr
http:/www.inria.fr:/prisme/personnel/devillers/anglais/determinant.html
Olivier Devillers has allowed the code to be distributed under
the LGPL (2012-02-16) saying "It is ok for LGPL distribution."
Copyright (c) 1995 by INRIA Prisme Project
BP 93 06902 Sophia Antipolis Cedex, France.
All rights reserved
- Version:
- 1.7
Method Summary |
static int |
orientationIndex(Coordinate p1,
Coordinate p2,
Coordinate q)
Returns the index of the direction of the point q relative to
a vector specified by p1-p2 . |
static int |
signOfDet2x2(double x1,
double y1,
double x2,
double y2)
Computes the sign of the determinant of the 2x2 matrix
with the given entries, in a robust way. |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
RobustDeterminant
public RobustDeterminant()
signOfDet2x2
public static int signOfDet2x2(double x1,
double y1,
double x2,
double y2)
- Computes the sign of the determinant of the 2x2 matrix
with the given entries, in a robust way.
- Returns:
- -1 if the determinant is negative,
orientationIndex
public static int orientationIndex(Coordinate p1,
Coordinate p2,
Coordinate q)
- Returns the index of the direction of the point
q
relative to
a vector specified by p1-p2
.
- Parameters:
p1
- the origin point of the vectorp2
- the final point of the vectorq
- the point to compute the direction to
- Returns:
- 1 if q is counter-clockwise (left) from p1-p2