ucar.units.TimeScaleUnit Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of udunits Show documentation
Show all versions of udunits Show documentation
The ucar.units Java package is for decoding and encoding formatted unit specifications (e.g. "m/s"), converting numeric values between compatible units (e.g. between "m/s" and "knot"), and for performing arithmetic operations on units (e.g. dividing one unit by another, or raising a unit to a power).
The newest version!
/*
* Copyright (c) 1998-2018 University Corporation for Atmospheric Research/Unidata
* See LICENSE for license information.
*/
package ucar.units;
import org.joda.time.format.DateTimeFormat;
import org.joda.time.format.DateTimeFormatter;
import javax.annotation.concurrent.Immutable;
import java.util.Date;
/**
* Provides support for a reference time unit whose origin is at a certain time.
*
* Instances of this class are immutable.
*
* @author Steven R. Emmerson
*/
@Immutable
public final class TimeScaleUnit extends UnitImpl {
private static final long serialVersionUID = 1L;
/**
* The date formatter.
*
* @serial
*/
static final DateTimeFormatter df_units = DateTimeFormat.forPattern("yyyy-MM-dd HH:mm:ss.SSS 'UTC'").withZoneUTC(); // joda-time
/**
* The second unit.
*/
static final BaseUnit SECOND;
static {
try {
SECOND = BaseUnit.getOrCreate(UnitName.newUnitName("second", null, "s"), BaseQuantity.TIME);
} catch (final Exception e) {
throw (ExceptionInInitializerError) new ExceptionInInitializerError().initCause(e);
}
}
///////////////////////////////////////////////////////
/**
* The reference time unit.
*
* @serial
*/
private final Unit _unit;
/**
* The time origin for this instance.
*
* @serial
*/
private final Date _origin;
/**
* Constructs from a reference unit and a time origin.
*
* @param unit The reference time unit.
* @param origin The time origin.
* @throws BadUnitException unit is not a unit of time.
*/
public TimeScaleUnit(final Unit unit, final Date origin)
throws BadUnitException, UnitSystemException {
this(unit, origin, null);
}
/**
* Constructs from a reference unit, a time origin, and an identifier.
*
* @param unit The reference time unit.
* @param origin The time origin.
* @param id The identifier.
* @throws BadUnitException unit is not a unit of time.
*/
public TimeScaleUnit(final Unit unit, final Date origin, final UnitName id)
throws BadUnitException, UnitSystemException {
super(id);
if (!unit.isCompatible(UnitSystemManager.instance().getBaseUnit(
BaseQuantity.TIME))) {
throw new BadUnitException("\"" + unit + "\" is not a unit of time");
}
_unit = unit;
_origin = origin;
}
static Unit getInstance(final Unit unit, final Date origin)
throws ShiftException {
try {
return unit instanceof TimeScaleUnit
? new TimeScaleUnit(((TimeScaleUnit) unit)._unit, origin)
: new TimeScaleUnit(unit, origin);
} catch (final Exception e) {
throw (ShiftException) new ShiftException(unit, origin)
.initCause(e);
}
}
/**
* Returns the reference unit.
*
* @return The reference unit.
*/
public Unit getUnit() {
return _unit;
}
/**
* Returns the time origin.
*
* @return The time origin.
*/
public Date getOrigin() {
return _origin;
}
/*
* From UnitImpl:
*/
/**
* Clones this unit, changing the identifier.
*
* @param id The new identifier.
* @return This unit with the new identifier.
*/
public Unit clone(final UnitName id) {
Unit clone;
try {
clone = new TimeScaleUnit(getUnit(), getOrigin(), id);
} catch (final UnitException e) {
clone = null; // can't happen
}
return clone;
}
@Override
public Unit shiftTo(final double origin) throws ShiftException {
Date newOrigin;
try {
newOrigin = new Date(_origin.getTime()
+ (long) (_unit.convertTo(origin, SECOND) * 1000));
} catch (final ConversionException e) {
throw (ShiftException) new ShiftException(this, origin)
.initCause(e);
}
try {
return new TimeScaleUnit(_unit, newOrigin);
} catch (final BadUnitException e) {
throw new AssertionError();
} catch (final UnitSystemException e) {
throw (ShiftException) new ShiftException(this, origin)
.initCause(e);
}
}
@Override
public Unit shiftTo(final Date origin) throws ShiftException {
return getInstance(_unit, origin);
}
/**
* Multiplies this unit by another unit. This operation is invalid.
*
* @param that The other unit.
* @return The product of multiplying this unit by the other unit.
* @throws MultiplyException Illegal operation. Always thrown.
*/
@Override
protected Unit myMultiplyBy(final Unit that) throws MultiplyException {
throw new MultiplyException(this);
}
/**
* Divides this unit by another unit. This operation is invalid.
*
* @param that The other unit.
* @return The quotient of dividing this unit by the other unit.
* @throws DivideException Illegal operation. Always thrown.
*/
@Override
protected Unit myDivideBy(final Unit that) throws DivideException {
throw new DivideException(this);
}
/**
* Divides this unit into another unit. This operation is invalid.
*
* @param that The other unit.
* @return The quotient of dividing this unit into the other unit.
* @throws DivideException Illegal operation. Always thrown.
*/
@Override
protected Unit myDivideInto(final Unit that) throws DivideException {
throw new DivideException(that, this);
}
/**
* Raises this unit to a power. This operation is invalid.
*
* @param power The power.
* @return The result of raising this unit to the power.
* @throws RaiseException Illegal operation. Always thrown.
*/
@Override
protected Unit myRaiseTo(final int power) throws RaiseException {
throw new RaiseException(this);
}
/**
* Returns the derived unit underlying the reference time unit.
*
* @return The derived unit underlying the reference time unit.
*/
public DerivedUnit getDerivedUnit() {
return getUnit().getDerivedUnit();
}
/**
* Provides support for Converter-s.
*/
protected static final class MyConverter extends ConverterImpl {
private final double offset;
private final Converter converter;
protected MyConverter(final TimeScaleUnit fromUnit, final Unit toUnit)
throws ConversionException {
super(fromUnit, toUnit);
converter = fromUnit.getUnit().getConverterTo(
((TimeScaleUnit) toUnit).getUnit());
offset = SI.SECOND.convertTo(
(fromUnit.getOrigin().getTime() - ((TimeScaleUnit) toUnit)
.getOrigin().getTime()) / 1000.0,
((TimeScaleUnit) toUnit).getUnit());
}
public double convert(final double amount) {
return converter.convert(amount) + offset;
}
public float[] convert(final float[] input, float[] output) {
output = converter.convert(input, output);
for (int i = input.length; --i >= 0; ) {
output[i] += offset;
}
return output;
}
public double[] convert(final double[] input, double[] output) {
output = converter.convert(input, output);
for (int i = input.length; --i >= 0; ) {
output[i] += offset;
}
return output;
}
}
/**
* Returns a Converter for converting numeric values from this unit to
* another unit.
*
* @param outputUnit The other unit. Shall be a TimeScaleUnit.
* @return A Converter.
* @throws ConversionException outputUnit is not a TimeScaleUnit.
*/
@Override
public Converter getConverterTo(final Unit outputUnit)
throws ConversionException {
return new MyConverter(this, outputUnit);
}
/**
* Indicates if numeric values in this unit are convertible to another unit.
*
* @param that The other unit.
* @return true if and only if numeric values in this unit are
* convertible to
* that.
*/
@Override
public final boolean isCompatible(final Unit that) {
return that instanceof TimeScaleUnit;
}
/**
* Indicates if this unit is semantically identical to an object.
*
* @param object The object.
* @return true if and only if this unit is semantically
* identical to object
* .
*/
@Override
public boolean equals(final Object object) {
if (this == object) {
return true;
}
if (!(object instanceof TimeScaleUnit)) {
return false;
}
final TimeScaleUnit that = (TimeScaleUnit) object;
return _origin.equals(that._origin) && _unit.equals(that._unit);
}
/**
* Returns the hash code of this instance.
*
* @return The hash code of this instance.
*/
@Override
public int hashCode() {
return getUnit().hashCode() ^ getOrigin().hashCode();
}
/**
* Indicates if this unit is dimensionless. TimeScaleUnit-s are never
* dimensionless.
*
* @return false.
*/
public boolean isDimensionless() {
return false; // a TimeScaleUnit is never dimensionless by definition
}
/**
* Returns the string representation of this unit.
*
* @return The string representation of this unit.
*/
@Override
public String toString() {
final String string = super.toString(); // get symbol or name
return string != null
? string
: getCanonicalString();
}
/**
* Returns the canonical string representation of the unit.
*
* @return The canonical string representation.
*/
public String getCanonicalString() {
/* change this, not thread-safe; require dependency of joda-time (!)
dateFormat = (SimpleDateFormat) DateFormat.getDateInstance(DateFormat.SHORT, Locale.US);
dateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
dateFormat.applyPattern(" 'since' yyyy-MM-dd HH:mm:ss.SSS 'UTC'");
*/
return getUnit().toString() + " since " + df_units.print(getOrigin().getTime());
}
}