org.apache.sis.measure

Class Angle

Object

Angle

All Implemented Interfaces:

Serializable, Comparable<Angle>, Formattable

Direct Known Subclasses:

ElevationAngle, Latitude, Longitude

public class Angle
extends Object
implements Comparable<Angle>, Formattable, Serializable

An angle in decimal degrees. An angle is the amount of rotation needed to bring one line or plane into coincidence with another. Various kind of angles are used in geographic information systems, some of them having a specialized class in Apache SIS:

• Latitude is an angle ranging from 0° at the equator to 90° at the poles.
• Longitude is an angle measured east-west from a prime meridian (usually Greenwich, but not necessarily).
• Azimuth is a direction given by an angle between 0° and 360° measured clockwise from North.
• Bearing is a direction given by an angle between 0° and 90° in a quadrant defined by a cardinal direction.
• Bearing is also sometime used in navigation for an angle relative to the vessel forward direction.
• Deflection angle is the angle between a line and the prolongation of a preceding line.
• Interior angle is an angle measured between two lines of sight.
• Elevation angle is the angular height from the horizontal plane to an object above the horizon.

Formatting angles

The recommended way to format angles is to instantiate an Angle­Format once, then to reuse it many times. As a convenience, Angle objects can also be formatted by the "%s" conversion specifier of Formatter, but this is less efficient for this class.

Immutability and thread safety

This class and the Latitude / Longitude subclasses are immutable, and thus inherently thread-safe. Other subclasses may or may not be immutable, at implementation choice (see Number for an example of a similar in purpose class having mutable subclasses).

Since:

0.3

See Also:

Latitude, Longitude, Angle­Format, Serialized Form

Defined in the sis-utility module

Constructor Summary

Constructors

Constructor and Description
Angle(double θ) Constructs a new angle with the specified value in decimal degrees.
Angle(String text) Constructs a newly allocated Angle object that contain the angular value represented by the string.

Method Summary

Modifier and Type	Method and Description
int	compareTo(Angle that) Compares two Angle objects numerically.
double	degrees() Returns the angle value in decimal degrees.
boolean	equals(Object object) Compares the specified object with this angle for equality.
void	formatTo(Formatter formatter, int flags, int width, int precision) Formats this angle using the provider formatter.
int	hashCode() Returns a hash code for this Angle object.
double	radians() Returns the angle value in radians.
String	toString() Returns a string representation of this Angle object.

Methods inherited from class Object

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

Constructor Detail

Angle

public Angle(double θ)

Constructs a new angle with the specified value in decimal degrees.

Parameters:

θ - angle in decimal degrees.

Angle

public Angle(String text)
      throws NumberFormatException

Constructs a newly allocated Angle object that contain the angular value represented by the string. The string should represent an angle in either fractional degrees (e.g. 45.5°) or degrees with minutes and seconds (e.g. 45°30').

This is a convenience constructor mostly for testing purpose, since it uses a fixed locale. Developers should consider using Angle­Format for end-user applications instead than this constructor.

Parameters:

text - a string to be converted to an Angle.

Throws:

Number­Format­Exception - if the string does not contain a parsable angle.

See Also:

Angle­Format.parse(String)

Method Detail

degrees

public double degrees()

Returns the angle value in decimal degrees.

Returns:

the angle value in decimal degrees.

radians

public double radians()

Returns the angle value in radians.

Returns:

the angle value in radians.

hashCode

public int hashCode()

Returns a hash code for this Angle object.

Overrides:

hash­Code in class Object

equals

public boolean equals(Object object)

Compares the specified object with this angle for equality.

Overrides:

equals in class Object

Parameters:

object - the object to compare with this angle for equality.

Returns:

true if the given object is equal to this angle.

compareTo

public int compareTo(Angle that)

Compares two Angle objects numerically. The comparison is done as if by the Double.compare(double, double) method.

Specified by:

compare­To in interface Comparable<Angle>

Parameters:

that - the angle to compare with this object for order.

Returns:

-1 if this angle is smaller than the given one, +1 if greater or 0 if equals.

toString

public String toString()

Returns a string representation of this Angle object. This is a convenience method mostly for debugging purpose, since it uses a fixed locale. Developers should consider using Angle­Format for end-user applications instead than this method.

Overrides:

to­String in class Object

See Also:

Angle­Format.format(double)

formatTo

public void formatTo(Formatter formatter,
                     int flags,
                     int width,
                     int precision)

Formats this angle using the provider formatter. This method is invoked when an Angle object is formatted using the "%s" conversion specifier of Formatter. Users don't need to invoke this method explicitely.

Special cases:

• If the precision is 0, then this method formats an empty string.
• If the precision is 1 and this angle is a Latitude or Longitude, then this method formats only the hemisphere symbol.
• Otherwise the precision, if positive, is given to Angle­Format.set­Maximum­Width(int).

Specified by:

format­To in interface Formattable

Parameters:

formatter - the formatter in which to format this angle.

flags - Formattable­Flags.LEFT_JUSTIFY for left alignment, or 0 for right alignment.

width - minimal number of characters to write, padding with ' ' if necessary.

precision - maximal number of characters to write, or -1 if no limit.