Package org.djunits.unit.si

Class SIDimensions

java.lang.Object

org.djunits.unit.si.SIDimensions

All Implemented Interfaces:

Serializable

public class SIDimensions
extends Object
implements Serializable

SIDimensions stores the dimensionality of a unit using the SI standards. Angle (rad) and solid angle (sr) have been added to be able to specify often used units regarding rotation.

Copyright (c) 2019-2022 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved.
BSD-style license. See DJUNITS License

Author:

Alexander Verbraeck

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
static int	NUMBER_DIMENSIONS	The (currently) 9 dimensions we take into account: rad, sr, kg, m, s, A, K, mol, cd.

Constructor Summary

Constructors

Modifier	Constructor	Description
	SIDimensions(byte[] dimensions)	Create an immutable SIDimensions instance based on a safe copy of a given dimensions specification.
protected	SIDimensions(byte[] numerator, byte[] denominator)	Create an immutable fractional SIDimensions instance based on a safe copy of a given specification, separated in a numerator and a denominator.
	SIDimensions(int angle, int solidAngle, int mass, int length, int time, int current, int temperature, int amountOfSubstance, int luminousIntensity)	Create an immutable SIDimensions instance based on a safe copy of a given dimensions specification.

Method Summary

Modifier and Type	Method	Description
static SIDimensions	add(SIDimensions dim1, SIDimensions dim2)	Add two SIDimensions and return the new SIDimensions.
boolean	equals(Object obj)
int	hashCode()
SIDimensions	invert()	Invert a set of SI dimensions; instead of m/s we get s/m.
boolean	isFractional()	Indicate whether this SIDImensions contains one or more fractional dimensions.
SIDimensions	minus(SIDimensions other)	Subtract a set of SI dimensions from this SIDimensions.
static SIDimensions	of(String siString)	Parse a string representing SI dimensions to an SIDimensions object.
SIDimensions	plus(SIDimensions other)	Add a set of SI dimensions to this SIDimensions.
String[]	siAbbreviations()	Returns a safe copy of the SI abbreviations (a public static final String[] is mutable).
static SIDimensions	subtract(SIDimensions dim1, SIDimensions dim2)	Subtract an SIDimensions (dim2) from another SIDimensions (dim1) and return the new SIDimensions.
String	toHTMLString(boolean divided, boolean separator)	Return a string such as "kgm/s2" or or "kg.m.s-2" from this SIDimensions.
String	toString()
String	toString(boolean divided, boolean separator)	Return a string such as "kgm/s2" or "kg.m/s2" or "kg.m.s-2" from this SIDimensions.
String	toString(boolean divided, boolean separator, boolean power)	Return a string such as "kgm/s2" or "kg.m/s^2" or "kg.m.s^-2" from this SIDimensions.
String	toString(boolean divided, String separator, String powerPrefix, String powerPostfix)	Return a string such as "kgm/s2" or "kg.m/s^2" or "kg.m.s^-2" from this SIDimensions.

Methods inherited from class java.lang.Object

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

Field Detail

NUMBER_DIMENSIONS

public static final int NUMBER_DIMENSIONS

The (currently) 9 dimensions we take into account: rad, sr, kg, m, s, A, K, mol, cd.

See Also:

Constant Field Values

Constructor Detail

SIDimensions

public SIDimensions(byte[] dimensions)

Create an immutable SIDimensions instance based on a safe copy of a given dimensions specification. As an example, speed is indicated as length = 1; time = -1 with the other dimensions equal to zero.

Parameters:

dimensions - byte[]; The (currently) 9 dimensions of the SI unit we distinguish: 0: angle (rad), 1: solid angle (sr), 2: mass (kg), 3: length (m), 4: time (s), 5: current (A), 6: temperature (K), 7: amount of substance (mol), 8: luminous intensity (cd).

SIDimensions

protected SIDimensions(byte[] numerator,
                       byte[] denominator)

Create an immutable fractional SIDimensions instance based on a safe copy of a given specification, separated in a numerator and a denominator.

Parameters:

numerator - byte[]; The (currently) 9 dimensions of the SI unit we distinguish: 0: angle (rad), 1: solid angle (sr), 2: mass (kg), 3: length (m), 4: time (s), 5: current (A), 6: temperature (K), 7: amount of substance (mol), 8: luminous intensity (cd).

denominator - byte[]; The (currently) 9 dimensions of the SI unit we distinguish: 0: angle (rad), 1: solid angle (sr), 2: mass (kg), 3: length (m), 4: time (s), 5: current (A), 6: temperature (K), 7: amount of substance (mol), 8: luminous intensity (cd).

SIDimensions

public SIDimensions(int angle,
                    int solidAngle,
                    int mass,
                    int length,
                    int time,
                    int current,
                    int temperature,
                    int amountOfSubstance,
                    int luminousIntensity)

Create an immutable SIDimensions instance based on a safe copy of a given dimensions specification.

Parameters:

angle - int; dimension of the angle (rad)

solidAngle - int; dimension of the solidAngle (sr)

mass - int; dimension of the mass (kg)

length - int; dimension of the length (m)

time - int; dimension of the time (s)

current - int; dimension of the current (A)

temperature - int; dimension of the temperature (K)

amountOfSubstance - int; dimension of the amount of substance (mol)

luminousIntensity - int; dimension of the luminous intensity (cd)

Method Detail

of

public static SIDimensions of(String siString)
                       throws UnitException

Parse a string representing SI dimensions to an SIDimensions object. Example: SIDimensions.of("kgm/s2") and SIDimensions.of("kgms-2") will both be translated to a dimensions object with vector {0,0,1,1,-2,0,0,0,0}. It is allowed to use 0 or 1 for the dimensions. Having the same unit in the numerator and the denominator is not seen as a problem: the values are subtracted from each other, so m/m will have a length dimensionality of 0. Dimensions between -9 and 9 are allowed. Spaces, periods and ^ are taken out, but other characters are not allowed and will lead to a UnitException. The order of allowed units is arbitrary, so "kg/ms2" is accepted as well as "kg/s^2.m".

Parameters:

siString - String; the string to parse

Returns:

SIDimension; the corresponding SI dimensions

Throws:

UnitException - when the string could not be parsed into dimensions

siAbbreviations

public String[] siAbbreviations()

Returns a safe copy of the SI abbreviations (a public static final String[] is mutable).

Returns:

String[]; a safe copy of the SI abbreviations

plus

public SIDimensions plus(SIDimensions other)

Add a set of SI dimensions to this SIDimensions. Note: as dimensions are considered to be immutable, a new dimension is returned. The original dimension (this) remains unaltered.

Parameters:

other - SIDimensions; the dimensions to add (usually as a result of multiplication of scalars)

Returns:

SIDimensions; the new dimensions with the dimensions of this object plus the dimensions in the parameter

minus

public SIDimensions minus(SIDimensions other)

Subtract a set of SI dimensions from this SIDimensions. Note: as dimensions are considered to be immutable, a new dimension is returned. The original dimension (this) remains unaltered.

Parameters:

other - SIDimensions; the dimensions to subtract (usually as a result of division of scalars)

Returns:

SIDimensions; the new dimensions with the dimensions of this object minus the dimensions in the parameter

invert

public SIDimensions invert()

Invert a set of SI dimensions; instead of m/s we get s/m. Note: as dimensions are considered to be immutable, a new dimension is returned. The original dimension (this) remains unaltered.

Returns:

SIDimensions; the new dimensions that are the inverse of the dimensions in this object

add

public static SIDimensions add(SIDimensions dim1,
                               SIDimensions dim2)

Add two SIDimensions and return the new SIDimensions. Usually, dimensions are added as a result of multiplication of scalars.

Parameters:

dim1 - SIDimensions; the first set of dimensions

dim2 - SIDimensions; the second set of dimensions

Returns:

the new dimensions with the sum of the dimensions in the parameters

subtract

public static SIDimensions subtract(SIDimensions dim1,
                                    SIDimensions dim2)

Subtract an SIDimensions (dim2) from another SIDimensions (dim1) and return the new SIDimensions. Usually, dimensions are added as a result of division of scalars.

Parameters:

dim1 - SIDimensions; the first set of dimensions

dim2 - SIDimensions; the second set of dimensions that will be subtracted from dim1

Returns:

the new dimensions with the difference of the dimensions in the parameters

isFractional

public boolean isFractional()

Indicate whether this SIDImensions contains one or more fractional dimensions.

Returns:

boolean; whether this SIDImensions contains one or more fractional dimensions

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

toString

public String toString(boolean divided,
                       String separator,
                       String powerPrefix,
                       String powerPostfix)

Return a string such as "kgm/s2" or "kg.m/s^2" or "kg.m.s^-2" from this SIDimensions.

Parameters:

divided - boolean; if true, return m/s2 for acceleration; if false return ms-2

separator - String; add this string between successive units, e.g. kg.m.s-2 instead of kgms-2

powerPrefix - String; the prefix for the power, e.g., "^" or "^"

powerPostfix - String; the postfix for the power, e.g., ""

Returns:

String; a formatted string for this SIDimensions

toString

public String toString(boolean divided,
                       boolean separator)

Return a string such as "kgm/s2" or "kg.m/s2" or "kg.m.s-2" from this SIDimensions.

Parameters:

divided - boolean; if true, return m/s2 for acceleration; if false return ms-2

separator - boolean; if true, add a period between successive units, e.g. kg.m.s-2 instead of kgms-2

Returns:

String; a formatted string describing this SIDimensions

toString

public String toString(boolean divided,
                       boolean separator,
                       boolean power)

Return a string such as "kgm/s2" or "kg.m/s^2" or "kg.m.s^-2" from this SIDimensions.

Parameters:

divided - boolean; if true, return m/s2 for acceleration; if false return ms-2

separator - boolean; if true, add a period between successive units, e.g. kg.m.s-2 instead of kgms-2

power - boolean; if true, add a ^ sign before the power, e.g., "kg.m^2/s^3" instead of "kg.m2/s3"

Returns:

String; a formatted string describing this SIDimensions

toHTMLString

public String toHTMLString(boolean divided,
                           boolean separator)

Return a string such as "kgm/s²" or or "kg.m.s^-2" from this SIDimensions.

Parameters:

divided - boolean; if true, return "m/s²" for acceleration; if false return "ms^-2"

separator - boolean; if true, add a period between successive units, e.g. kg.m.s^-2

Returns:

String; a formatted string describing this SIDimensions

toString

public String toString()

Overrides:

toString in class Object