Files
allwpilib/wpiunits/src/main/java/edu/wpi/first/units/Units.java
2024-01-19 23:42:09 -08:00

403 lines
15 KiB
Java

// Copyright (c) FIRST and other WPILib contributors.
// Open Source Software; you can modify and/or share it under the terms of
// the WPILib BSD license file in the root directory of this project.
package edu.wpi.first.units;
import java.util.Locale;
/** Contains a set of predefined units. */
public final class Units {
private Units() {
// Prevent instantiation
}
// Pseudo-classes describing the more common units of measure.
/**
* Used as an internal placeholder value when a specific unit type cannot be determined. Do not
* use this directly.
*/
@SuppressWarnings("rawtypes")
public static final Unit AnonymousBaseUnit = new Dimensionless(1, "<?>", "<?>");
// Distance
/** The base unit of distance. */
public static final Distance Meters = BaseUnits.Distance;
/** 1/1000 of a {@link #Meters Meter}. */
public static final Distance Millimeters = Milli(Meters, "Millimeter", "mm");
/** 1/100 of a {@link #Meters Meter}. */
public static final Distance Centimeters =
derive(Meters).splitInto(100).named("Centimeter").symbol("cm").make();
/** 25.4/1000 of a {@link #Meters Meter} and 1/12 of a {@link #Feet Foot}. */
public static final Distance Inches =
derive(Millimeters).aggregate(25.4).named("Inch").symbol("in").make();
/** 304.8/1000 of a {@link #Meters Meter}, or 12 {@link #Inches}. */
public static final Distance Feet =
derive(Inches).aggregate(12).named("Foot").symbol("ft").make();
// Time
/** The base unit of time. */
public static final Time Seconds = BaseUnits.Time;
/** Alias for {@link #Seconds} to make combined unit definitions read more smoothly. */
public static final Time Second = Seconds; // singularized alias
/** 1/1000 of a {@link #Seconds Second}. */
public static final Time Milliseconds = Milli(Seconds);
/** Alias for {@link #Milliseconds} to make combined unit definitions read more smoothly. */
public static final Time Millisecond = Milliseconds; // singularized alias
/** 1/1,000,000 of a {@link #Seconds Second}. */
public static final Time Microseconds = Micro(Seconds);
/** Alias for {@link #Microseconds} to make combined unit definitions read more smoothly. */
public static final Time Microsecond = Microseconds; // singularized alias
/** 60 {@link #Seconds}. */
public static final Time Minutes =
derive(Seconds).aggregate(60).named("Minute").symbol("min").make();
/** Alias for {@link #Minutes} to make combined unit definitions read more smoothly. */
public static final Time Minute = Minutes; // singularized alias
// Angle
/**
* The base SI unit of angle, represented by the distance that the radius of a unit circle can
* wrap around its circumference.
*/
public static final Angle Radians = BaseUnits.Angle;
/**
* A single turn of an object around an external axis. Numerically equivalent to {@link
* #Rotations}, but may be semantically more expressive in certain scenarios.
*/
public static final Angle Revolutions = new Angle(2 * Math.PI, "Revolution", "R");
/**
* A single turn of an object around an internal axis. Numerically equivalent to {@link
* #Revolutions}, but may be semantically more expressive in certain scenarios.
*/
public static final Angle Rotations = new Angle(2 * Math.PI, "Rotation", "R"); // alias revolution
/** 1/360 of a turn around a circle, or 1/57.3 {@link #Radians}. */
public static final Angle Degrees =
derive(Revolutions).splitInto(360).named("Degree").symbol("°").make();
// Velocity
/**
* The standard SI unit of linear velocity, equivalent to travelling at a rate of one {@link
* #Meters Meter} per {@link #Second}.
*/
public static final Velocity<Distance> MetersPerSecond = Meters.per(Second);
/**
* A unit of linear velocity equivalent to travelling at a rate one {@link #Feet Foot} per {@link
* #Second}.
*/
public static final Velocity<Distance> FeetPerSecond = Feet.per(Second);
/**
* A unit of linear velocity equivalent to travelling at a rate of one {@link #Inches Inch} per
* {@link #Second}.
*/
public static final Velocity<Distance> InchesPerSecond = Inches.per(Second);
/**
* A unit of angular velocity equivalent to spinning at a rate of one {@link #Revolutions
* Revolution} per {@link #Second}.
*/
public static final Velocity<Angle> RevolutionsPerSecond = Revolutions.per(Second);
/**
* A unit of angular velocity equivalent to spinning at a rate of one {@link #Rotations Rotation}
* per {@link #Second}.
*/
public static final Velocity<Angle> RotationsPerSecond = Rotations.per(Second);
/**
* A unit of angular velocity equivalent to spinning at a rate of one {@link #Rotations Rotation}
* per {@link #Minute}. Motor spec sheets often list maximum speeds in terms of RPM.
*/
public static final Velocity<Angle> RPM = Rotations.per(Minute);
/**
* The standard SI unit of angular velocity, equivalent to spinning at a rate of one {@link
* #Radians Radian} per {@link #Second}.
*/
public static final Velocity<Angle> RadiansPerSecond = Radians.per(Second);
/**
* A unit of angular velocity equivalent to spinning at a rate of one {@link #Degrees Degree} per
* {@link #Second}.
*/
public static final Velocity<Angle> DegreesPerSecond = Degrees.per(Second);
// Acceleration
/**
* The standard SI unit of linear acceleration, equivalent to accelerating at a rate of one {@link
* #Meters Meter} per {@link #Second} every second.
*/
public static final Velocity<Velocity<Distance>> MetersPerSecondPerSecond =
MetersPerSecond.per(Second);
/**
* A unit of acceleration equivalent to the pull of gravity on an object at sea level on Earth.
*/
public static final Velocity<Velocity<Distance>> Gs =
derive(MetersPerSecondPerSecond).aggregate(9.80665).named("G").symbol("G").make();
// Mass
/** The base SI unit of mass. */
public static final Mass Kilograms = BaseUnits.Mass;
/** 1/1000 of a {@link #Kilograms Kilogram}. */
public static final Mass Grams = Milli(Kilograms, "Gram", "g");
/**
* A unit of mass equivalent to approximately 453 {@link #Grams}. This is <i>not</i> equivalent to
* pounds-force, which is the amount of force required to accelerate an object with one pound of
* mass at a rate of one {@link #Gs G}.
*/
public static final Mass Pounds =
derive(Grams).aggregate(453.592).named("Pound").symbol("lb.").make();
/** 1/16 of a {@link #Pounds Pound}. */
public static final Mass Ounces =
derive(Pounds).splitInto(16).named("Ounce").symbol("oz.").make();
// Unitless
/** A dimensionless unit that performs no scaling whatsoever. */
public static final Dimensionless Value = BaseUnits.Value;
/**
* A dimensionless unit equal to to 1/100th of a {@link #Value}. A measurement of {@code
* Percent.of(42)} would be equivalent to {@code Value.of(0.42)}.
*/
public static final Dimensionless Percent =
derive(Value).splitInto(100).named("Percent").symbol("%").make();
// Voltage
/** The base unit of electric potential. */
public static final Voltage Volts = BaseUnits.Voltage;
/**
* 1/1000 of a {@link #Volts Volt}. Useful when dealing with low-voltage applications like LED
* drivers or low-power circuits.
*/
public static final Voltage Millivolts = Milli(Volts);
// Current
/** The base unit of electrical current. */
public static final Current Amps = BaseUnits.Current;
/**
* A unit equal to 1/1000 of an {@link #Amps Amp}. Useful when dealing with low-current
* applications like LED drivers or low-power circuits.
*/
public static final Current Milliamps = Milli(Amps);
// Energy
/** The base unit of energy. */
public static final Energy Joules = BaseUnits.Energy;
/**
* A unit equal to 1/1000 of a {@link #Joules Joule}. Useful when dealing with lower-power
* applications.
*/
public static final Energy Millijoules = Milli(Joules);
/**
* A unit equal to 1,000 {@link #Joules}. Useful when dealing with higher-level robot energy
* usage.
*/
public static final Energy Kilojoules = Kilo(Joules);
// Power
/** The base unit of power. Equivalent to one {@link #Joules Joule} per {@link #Second}. */
public static final Power Watts = BaseUnits.Power;
/**
* A unit equal to 1/1000 of a {@link #Watts Watt}. Useful when dealing with lower-power
* applications.
*/
public static final Power Milliwatts = Milli(Watts);
/**
* A unit equal to 745.7 {@link #Watts}. May be useful when dealing with high-power gearboxes and
* motors.
*/
public static final Power Horsepower =
derive(Watts).aggregate(745.7).named("Horsepower").symbol("HP").make();
// Temperature
/**
* The base unit of temperature, where a value of 0 corresponds with absolutely zero energy in the
* measured system. Not particularly useful for robots unless you're cooling motors with liquid
* helium.
*/
public static final Temperature Kelvin = BaseUnits.Temperature;
/**
* The base SI unit of temperature, where a value of 0 roughly corresponds to the freezing point
* of water and a value of 100 corresponds to the boiling point. Electronics tend to exhibit
* degraded performance or damage above 90 degrees Celsius.
*/
public static final Temperature Celsius =
derive(Kelvin).offset(+273.15).named("Celsius").symbol("°C").make();
/**
* The base imperial (American) unit of temperature, where a value of 32 roughly corresponds to
* the freezing point of water and a value of 212 corresponds to the boiling point.
*/
public static final Temperature Fahrenheit =
derive(Celsius)
.mappingInputRange(0, 100)
.toOutputRange(32, 212)
.named("Fahrenheit")
.symbol("°F")
.make();
// Standard feedforward units for kV and kA.
// kS and kG are just volts, which is already defined earlier
/**
* A standard unit for measuring linear mechanisms' feedforward voltages based on a model of the
* system and a desired commanded linear velocity.
*/
public static final Per<Voltage, Velocity<Distance>> VoltsPerMeterPerSecond =
Volts.per(MetersPerSecond);
/**
* A standard unit for measuring linear mechanisms' feedforward voltages based on a model of the
* system and a desired commanded linear acceleration.
*/
public static final Per<Voltage, Velocity<Velocity<Distance>>> VoltsPerMeterPerSecondSquared =
Volts.per(MetersPerSecondPerSecond);
/**
* A standard unit for measuring angular mechanisms' feedforward voltages based on a model of the
* system and a desired commanded angular velocity.
*/
public static final Per<Voltage, Velocity<Angle>> VoltsPerRadianPerSecond =
Volts.per(RadiansPerSecond);
/**
* A standard unit for measuring angular mechanisms' feedforward voltages based on a model of the
* system and a desired commanded angular acceleration.
*/
public static final Per<Voltage, Velocity<Velocity<Angle>>> VoltsPerRadianPerSecondSquared =
Volts.per(RadiansPerSecond.per(Second));
/**
* Creates a unit equal to a thousandth of the base unit, eg Milliseconds = Milli(Units.Seconds).
*
* @param <U> the type of the unit
* @param baseUnit the unit being derived from. This does not have to be the base unit of measure
* @param name the name of the new derived unit
* @param symbol the symbol of the new derived unit
* @return the milli-unit
*/
@SuppressWarnings({"PMD.MethodName", "checkstyle:methodname"})
public static <U extends Unit<U>> U Milli(Unit<U> baseUnit, String name, String symbol) {
return derive(baseUnit).splitInto(1000).named(name).symbol(symbol).make();
}
/**
* Creates a unit equal to a thousandth of the base unit, eg Milliseconds = Milli(Units.Seconds).
*
* @param <U> the type of the unit
* @param baseUnit the unit being derived from. This does not have to be the base unit of measure
* @return the milli-unit
*/
@SuppressWarnings({"PMD.MethodName", "checkstyle:methodname"})
public static <U extends Unit<U>> U Milli(Unit<U> baseUnit) {
return Milli(
baseUnit, "Milli" + baseUnit.name().toLowerCase(Locale.ROOT), "m" + baseUnit.symbol());
}
/**
* Creates a unit equal to a millionth of the base unit, eg {@code Microseconds =
* Micro(Units.Seconds, "Microseconds", 'us")}.
*
* @param <U> the type of the unit
* @param baseUnit the unit being derived from. This does not have to be the base unit of measure
* @param name the name of the new derived unit
* @param symbol the symbol of the new derived unit
* @return the micro-unit
*/
@SuppressWarnings({"PMD.MethodName", "checkstyle:methodname"})
public static <U extends Unit<U>> U Micro(Unit<U> baseUnit, String name, String symbol) {
return derive(baseUnit).splitInto(1_000_000).named(name).symbol(symbol).make();
}
/**
* Creates a unit equal to a millionth of the base unit, eg Microseconds = Micro(Units.Seconds).
*
* @param <U> the type of the unit
* @param baseUnit the unit being derived from. This does not have to be the base unit of measure
* @return the micro-unit
*/
@SuppressWarnings({"PMD.MethodName", "checkstyle:methodname"})
public static <U extends Unit<U>> U Micro(Unit<U> baseUnit) {
return Micro(
baseUnit, "Micro" + baseUnit.name().toLowerCase(Locale.ROOT), "u" + baseUnit.symbol());
}
/**
* Creates a unit equal to a thousand of the base unit, eg Kilograms = Kilo(Units.Grams).
*
* @param <U> the type of the unit
* @param baseUnit the unit being derived from. This does not have to be the base unit of measure
* @param name the name of the new derived unit
* @param symbol the symbol of the new derived unit
* @return the kilo-unit
*/
@SuppressWarnings({"PMD.MethodName", "checkstyle:methodname"})
public static <U extends Unit<U>> U Kilo(Unit<U> baseUnit, String name, String symbol) {
return derive(baseUnit).aggregate(1000).named(name).symbol(symbol).make();
}
/**
* Creates a unit equal to a thousand of the base unit, eg Kilograms = Kilo(Units.Grams).
*
* @param <U> the type of the unit
* @param baseUnit the unit being derived from. This does not have to be the base unit of measure
* @return the kilo-unit
*/
@SuppressWarnings({"PMD.MethodName", "checkstyle:methodname"})
public static <U extends Unit<U>> U Kilo(Unit<U> baseUnit) {
return Kilo(
baseUnit, "Kilo" + baseUnit.name().toLowerCase(Locale.ROOT), "K" + baseUnit.symbol());
}
/**
* Creates a new unit builder object based on a given input unit. The builder can be used to
* fluently describe a new unit in terms of its relation to the base unit.
*
* @param unit the base unit from which to derive a new unit
* @param <U> the dimension of the unit to derive
* @return a builder object
*/
@SuppressWarnings("unchecked")
public static <U extends Unit<U>> UnitBuilder<U> derive(Unit<U> unit) {
return new UnitBuilder<>((U) unit);
}
/**
* Returns an anonymous unit for use when a specific unit type is not known. Do not use this
* directly.
*
* @param <U> the dimension of the desired anonymous unit
* @return the anonymous unit
*/
@SuppressWarnings("unchecked")
public static <U extends Unit<U>> U anonymous() {
return (U) AnonymousBaseUnit;
}
}