org.apache.commons.geometry.spherical.oned

Class CutAngle

java.lang.Object

org.apache.commons.geometry.core.partitioning.AbstractHyperplane<Point1S>

org.apache.commons.geometry.spherical.oned.CutAngle

All Implemented Interfaces:

Hyperplane<Point1S>

public final class CutAngle
extends AbstractHyperplane<Point1S>

Class representing an oriented point in 1-dimensional spherical space, meaning an azimuth angle and a direction (increasing or decreasing angles) along the circle.

Hyperplanes split the spaces they are embedded in into three distinct parts: the hyperplane itself, a plus side and a minus side. However, since spherical space wraps around, a single oriented point is not sufficient to partition the space; any point could be classified as being on the plus or minus side of a hyperplane depending on the direction that the circle is traversed. The approach taken in this class to address this issue is to (1) define a second, implicit cut point at 0pi and (2) define the domain of hyperplane points (for partitioning purposes) to be the range [0, 2pi). Each hyperplane then splits the space into the intervals [0, x] and [x, 2pi), where x is the location of the hyperplane. One way to visualize this is to picture the circle as a cake that has already been cut at 0pi. Each hyperplane then specifies the location of the second cut of the cake, with the plus and minus sides being the pieces thus cut.

Note that with the hyperplane partitioning rules described above, the hyperplane at 0pi is unique in that it has the entire space on one side (minus the hyperplane itself) and no points whatsoever on the other. This is very different from hyperplanes in Euclidean space, which always have infinitely many points on both sides.

Instances of this class are guaranteed to be immutable.

See Also:

CutAngles

Method Summary

Modifier and Type	Method and Description
HyperplaneLocation	classify(Point1S pt)
boolean	eq(CutAngle other, Precision.DoubleEquivalence precision) Return true if this instance should be considered equivalent to the argument, using the given precision context for comparison.
boolean	equals(Object obj)
double	getAzimuth() Get the location of the hyperplane as a single value.
double	getNormalizedAzimuth() Get the location of the hyperplane as a single value, normalized to the range [0, 2pi).
Point1S	getPoint() Get the location of the hyperplane as a point.
int	hashCode()
boolean	isPositiveFacing() Return true if the hyperplane is oriented with its plus side pointing toward increasing angles.
double	offset(Point1S pt)
Point1S	project(Point1S pt)
CutAngle	reverse()
boolean	similarOrientation(Hyperplane<Point1S> other)
HyperplaneConvexSubset<Point1S>	span()
String	toString()
CutAngle	transform(Transform<Point1S> transform)

Methods inherited from class org.apache.commons.geometry.core.partitioning.AbstractHyperplane

contains, getPrecision

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

getPoint

public Point1S getPoint()

Get the location of the hyperplane as a point.

Returns:

the hyperplane location as a point

See Also:

getAzimuth()

getAzimuth

public double getAzimuth()

Get the location of the hyperplane as a single value. This is equivalent to cutAngle.getPoint().getAzimuth().

Returns:

the location of the hyperplane as a single value.

See Also:

getPoint(), Point1S.getAzimuth()

getNormalizedAzimuth

public double getNormalizedAzimuth()

Get the location of the hyperplane as a single value, normalized to the range [0, 2pi). This is equivalent to cutAngle.getPoint().getNormalizedAzimuth().

Returns:

the location of the hyperplane, normalized to the range [0, 2pi)

See Also:

getPoint(), Point1S.getNormalizedAzimuth()

isPositiveFacing

public boolean isPositiveFacing()

Return true if the hyperplane is oriented with its plus side pointing toward increasing angles.

Returns:

true if the hyperplane is facing in the direction of increasing angles

eq

public boolean eq(CutAngle other,
                  Precision.DoubleEquivalence precision)

Return true if this instance should be considered equivalent to the argument, using the given precision context for comparison.

The instances are considered equivalent if they

1. have equivalent point locations (points separated by multiples of 2pi are considered equivalent) and
2. point in the same direction.

Parameters:

other - point to compare with

precision - precision context to use for the comparison

Returns:

true if this instance should be considered equivalent to the argument

See Also:

Point1S.eq(Point1S, Precision.DoubleEquivalence)

offset

public double offset(Point1S pt)

classify

public HyperplaneLocation classify(Point1S pt)

Specified by:

classify in interface Hyperplane<Point1S>

Overrides:

classify in class AbstractHyperplane<Point1S>

project

public Point1S project(Point1S pt)

reverse

public CutAngle reverse()

transform

public CutAngle transform(Transform<Point1S> transform)

similarOrientation

public boolean similarOrientation(Hyperplane<Point1S> other)

span

public HyperplaneConvexSubset<Point1S> span()

Since there are no subspaces in spherical 1D space, this method effectively returns a stub implementation of HyperplaneConvexSubset, the main purpose of which is to support the proper functioning of the partitioning code.

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

toString

public String toString()

Overrides:

toString in class Object