| /** |
| * Copyright (c) 2005, 2010, Werner Keil, Ikayzo and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * Werner Keil, Ikayzo and others - initial API and implementation |
| */ |
| package org.eclipse.uomo.units.impl; |
| |
| import java.io.Serializable; |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| import org.eclipse.uomo.units.AbstractConverter; |
| import org.eclipse.uomo.units.AbstractUnit; |
| import org.unitsofmeasurement.quantity.Quantity; |
| import org.unitsofmeasurement.unit.Dimension; |
| import org.unitsofmeasurement.unit.IncommensurableException; |
| import org.unitsofmeasurement.unit.UnconvertibleException; |
| import org.unitsofmeasurement.unit.Unit; |
| import org.unitsofmeasurement.unit.UnitConverter; |
| |
| import com.ibm.icu.util.Measure; |
| |
| /** |
| * <p> This class represents units formed by the product of rational powers of |
| * existing units.</p> |
| * |
| * <p> This class maintains the canonical form of this product (simplest form |
| * after factorization). For example: <code>METRE.pow(2).divide(METRE)</code> |
| * returns <code>METRE</code>.</p> |
| * |
| * @param <Q> The type of the quantity measured by this unit. |
| * |
| * @author <a href="mailto:jean-marie@dautelle.com">Jean-Marie Dautelle</a> |
| * @author <a href="mailto:units@catmedia.us">Werner Keil</a> |
| * @version 1.3 ($Revision: 212 $), $Date: 2010-09-13 23:50:44 +0200 (Mo, 13 Sep 2010) $ |
| * @see AbstractUnit#multiply(AbstractUnit) |
| * @see AbstractUnit#divide(AbstractUnit) |
| * @see AbstractUnit#pow(int) |
| * @see AbstractUnit#root(int) |
| */ |
| public final class ProductUnit<Q extends Quantity<Q>> extends AbstractUnit<Q> implements Unit<Q> { |
| |
| /** |
| * For cross-version compatibility. |
| */ |
| private static final long serialVersionUID = -736056598162783537L; |
| |
| /** |
| * Holds the units composing this product unit. |
| */ |
| private final Element[] elements; |
| |
| /** |
| * Holds the hashcode (optimization). |
| */ |
| private int hashCode; |
| |
| /** |
| * Default constructor (used solely to create <code>ONE</code> instance). |
| */ |
| public ProductUnit() { |
| elements = new Element[0]; |
| } |
| |
| /** |
| * Copy constructor (allows for parameterization of product units). |
| * |
| * @param productUnit the product unit source. |
| * @throws ClassCastException if the specified unit is not a product unit. |
| */ |
| public ProductUnit(Unit<?> productUnit) { |
| this.elements = ((ProductUnit<?>) productUnit).elements; |
| } |
| |
| /** |
| * Product unit constructor. |
| * |
| * @param elements the product elements. |
| */ |
| private ProductUnit(Element[] elements) { |
| this.elements = elements; |
| } |
| |
| /** |
| * Returns the unit defined from the product of the specified elements. |
| * |
| * @param leftElems left multiplicand elements. |
| * @param rightElems right multiplicand elements. |
| * @return the corresponding unit. |
| */ |
| @SuppressWarnings({ "unchecked", "rawtypes" }) |
| private static Unit<?> getInstance(Element[] leftElems, |
| Element[] rightElems) { |
| |
| // Merges left elements with right elements. |
| Element[] result = new Element[leftElems.length + rightElems.length]; |
| int resultIndex = 0; |
| for (int i = 0; i < leftElems.length; i++) { |
| Unit<?> unit = leftElems[i].unit; |
| int p1 = leftElems[i].pow; |
| int r1 = leftElems[i].root; |
| int p2 = 0; |
| int r2 = 1; |
| for (int j = 0; j < rightElems.length; j++) { |
| if (unit.equals(rightElems[j].unit)) { |
| p2 = rightElems[j].pow; |
| r2 = rightElems[j].root; |
| break; // No duplicate. |
| } |
| } |
| int pow = (p1 * r2) + (p2 * r1); |
| int root = r1 * r2; |
| if (pow != 0) { |
| int gcd = gcd(Math.abs(pow), root); |
| result[resultIndex++] = new Element(unit, pow / gcd, root / gcd); |
| } |
| } |
| |
| // Appends remaining right elements not merged. |
| for (int i = 0; i < rightElems.length; i++) { |
| AbstractUnit<?> unit = (AbstractUnit<?>) rightElems[i].unit; |
| boolean hasBeenMerged = false; |
| for (int j = 0; j < leftElems.length; j++) { |
| if (unit.equals(leftElems[j].unit)) { |
| hasBeenMerged = true; |
| break; |
| } |
| } |
| if (!hasBeenMerged) |
| result[resultIndex++] = rightElems[i]; |
| } |
| |
| // Returns or creates instance. |
| if (resultIndex == 0) |
| return (Unit<?>) AbstractUnit.ONE; |
| else if ((resultIndex == 1) && (result[0].pow == result[0].root)) |
| return (Unit<? extends Measure>) result[0].unit; |
| else { |
| Element[] elems = new Element[resultIndex]; |
| for (int i = 0; i < resultIndex; i++) { |
| elems[i] = result[i]; |
| } |
| return new ProductUnit(elems); |
| } |
| } |
| |
| /** |
| * Returns the product of the specified units. |
| * |
| * @param left the left unit operand. |
| * @param right the right unit operand. |
| * @return <code>left * right</code> |
| */ |
| public static Unit<?> getProductInstance(Unit<?> left, |
| Unit<?> right) { |
| Element[] leftElems; |
| if (left instanceof ProductUnit<?>) |
| leftElems = ((ProductUnit<?>) left).elements; |
| else |
| leftElems = new Element[]{new Element(left, 1, 1)}; |
| Element[] rightElems; |
| if (right instanceof ProductUnit<?>) |
| rightElems = ((ProductUnit<?>) right).elements; |
| else |
| rightElems = new Element[]{new Element(right, 1, 1)}; |
| return getInstance(leftElems, rightElems); |
| } |
| |
| /** |
| * Returns the quotient of the specified units. |
| * |
| * @param left the dividend unit operand. |
| * @param right the divisor unit operand. |
| * @return <code>dividend / divisor</code> |
| */ |
| public static Unit<?> getQuotientInstance(Unit<?> left, |
| Unit<?> right) { |
| Element[] leftElems; |
| if (left instanceof ProductUnit<?>) |
| leftElems = ((ProductUnit<?>) left).elements; |
| else |
| leftElems = new Element[]{new Element(left, 1, 1)}; |
| Element[] rightElems; |
| if (right instanceof ProductUnit<?>) { |
| Element[] elems = ((ProductUnit<?>) right).elements; |
| rightElems = new Element[elems.length]; |
| for (int i = 0; i < elems.length; i++) { |
| rightElems[i] = new Element(elems[i].unit, -elems[i].pow, |
| elems[i].root); |
| } |
| } else |
| rightElems = new Element[]{new Element(right, -1, 1)}; |
| return (AbstractUnit<?>) getInstance(leftElems, rightElems); |
| } |
| |
| /** |
| * Returns the product unit corresponding to the specified root of the |
| * specified unit. |
| * |
| * @param unit the unit. |
| * @param n the root's order (n > 0). |
| * @return <code>unit^(1/nn)</code> |
| * @throws ArithmeticException if <code>n == 0</code>. |
| */ |
| public static Unit<?> getRootInstance(Unit<?> unit, int n) { |
| Element[] unitElems; |
| if (unit instanceof ProductUnit<?>) { |
| Element[] elems = ((ProductUnit<?>) unit).elements; |
| unitElems = new Element[elems.length]; |
| for (int i = 0; i < elems.length; i++) { |
| int gcd = gcd(Math.abs(elems[i].pow), elems[i].root * n); |
| unitElems[i] = new Element(elems[i].unit, elems[i].pow / gcd, |
| elems[i].root * n / gcd); |
| } |
| } else |
| unitElems = new Element[]{new Element(unit, 1, n)}; |
| return getInstance(unitElems, new Element[0]); |
| } |
| |
| /** |
| * Returns the product unit corresponding to this unit raised to the |
| * specified exponent. |
| * |
| * @param unit the unit. |
| * @param nn the exponent (nn > 0). |
| * @return <code>unit^n</code> |
| */ |
| static Unit<?> getPowInstance(AbstractUnit<?> unit, int n) { |
| Element[] unitElems; |
| if (unit instanceof ProductUnit<?>) { |
| Element[] elems = ((ProductUnit<?>) unit).elements; |
| unitElems = new Element[elems.length]; |
| for (int i = 0; i < elems.length; i++) { |
| int gcd = gcd(Math.abs(elems[i].pow * n), elems[i].root); |
| unitElems[i] = new Element(elems[i].unit, elems[i].pow * n / gcd, elems[i].root / gcd); |
| } |
| } else |
| unitElems = new Element[]{new Element(unit, n, 1)}; |
| return getInstance(unitElems, new Element[0]); |
| } |
| |
| /** |
| * Returns the number of unit elements in this product. |
| * |
| * @return the number of unit elements. |
| */ |
| public int getUnitCount() { |
| return elements.length; |
| } |
| |
| /** |
| * Returns the unit element at the specified position. |
| * |
| * @param index the index of the unit element to return. |
| * @return the unit element at the specified position. |
| * @throws IndexOutOfBoundsException if index is out of range |
| * <code>(index < 0 || index >= getUnitCount())</code>. |
| */ |
| @SuppressWarnings("unchecked") |
| public Unit<? extends Measure> getUnit(int index) { |
| return (Unit<? extends Measure>) elements[index].getUnit(); |
| } |
| |
| /** |
| * Returns the power exponent of the unit element at the specified position. |
| * |
| * @param index the index of the unit element. |
| * @return the unit power exponent at the specified position. |
| * @throws IndexOutOfBoundsException if index is out of range |
| * <code>(index < 0 || index >= getUnitCount())</code>. |
| */ |
| public int getUnitPow(int index) { |
| return elements[index].getPow(); |
| } |
| |
| /** |
| * Returns the root exponent of the unit element at the specified position. |
| * |
| * @param index the index of the unit element. |
| * @return the unit root exponent at the specified position. |
| * @throws IndexOutOfBoundsException if index is out of range |
| * <code>(index < 0 || index >= getUnitCount())</code>. |
| */ |
| public int getUnitRoot(int index) { |
| return elements[index].getRoot(); |
| } |
| |
| @Override |
| public Map<Unit<?>, Integer> getProductUnits() { |
| Map<Unit<?>, Integer> units = new HashMap<Unit<?>, Integer>(); |
| for (int i = 0; i < getUnitCount(); i++) { |
| units.put(getUnit(i), getUnitPow(i)); |
| } |
| return units; |
| } |
| |
| @Override |
| public boolean equals(Object that) { |
| if (this == that) |
| return true; |
| if (!(that instanceof ProductUnit<?>)) |
| return false; |
| // Two products are equals if they have the same elements |
| // regardless of the elements' order. |
| Element[] elems = ((ProductUnit<?>) that).elements; |
| if (elements.length != elems.length) |
| return false; |
| for (int i = 0; i < elements.length; i++) { |
| boolean unitFound = false; |
| Element e = elements[i]; |
| for (int j = 0; j < elems.length; j++) { |
| if (e.unit.equals(elems[j].unit)) |
| if ((e.pow != elems[j].pow) || (e.root != elems[j].root)) |
| return false; |
| else { |
| unitFound = true; |
| break; |
| } |
| } |
| if (!unitFound) |
| return false; |
| } |
| return true; |
| } |
| |
| @Override |
| public int hashCode() { |
| if (this.hashCode != 0) |
| return this.hashCode; |
| int code = 0; |
| for (int i = 0; i < elements.length; i++) { |
| code += elements[i].unit.hashCode() * (elements[i].pow * 3 - elements[i].root * 2); |
| } |
| this.hashCode = code; |
| return code; |
| } |
| |
| @Override |
| public final UnitConverter getConverterToMetric() { |
| if (hasOnlyUnscaledMetricUnits()) // Product of standard units is a standard unit itself. |
| return AbstractConverter.IDENTITY; |
| UnitConverter converter = AbstractConverter.IDENTITY; |
| for (int i = 0; i < elements.length; i++) { |
| Element e = elements[i]; |
| @SuppressWarnings("rawtypes") |
| UnitConverter cvtr = ((AbstractUnit) e.unit).getConverterToMetric(); |
| if (!(cvtr.isLinear())) |
| throw new UnsupportedOperationException(e.unit + " is non-linear, cannot convert"); |
| if (e.root != 1) |
| throw new UnsupportedOperationException(e.unit + " holds a base unit with fractional exponent"); |
| int pow = e.pow; |
| if (pow < 0) { // Negative power. |
| pow = -pow; |
| cvtr = cvtr.inverse(); |
| } |
| for (int j = 0; j < pow; j++) { |
| converter = converter.concatenate(cvtr); |
| } |
| } |
| return converter; |
| } |
| |
| /** |
| * Indicates if this product unit is a standard unit. |
| * |
| * @return <code>true</code> if all elements are standard units; |
| * <code>false</code> otherwise. |
| */ |
| private boolean hasOnlyUnscaledMetricUnits() { |
| for (int i = 0; i < elements.length; i++) { |
| AbstractUnit<?> u = (AbstractUnit<?>) elements[i].unit; |
| if (!u.isUnscaledMetric()) |
| return false; |
| } |
| return true; |
| } |
| |
| @Override |
| public Dimension getDimension() { |
| Dimension dimension = DimensionImpl.NONE; |
| for (int i = 0; i < this.getUnitCount(); i++) { |
| Unit<?> unit = this.getUnit(i); |
| Dimension d = unit.getDimension().pow(this.getUnitPow(i)).root(this.getUnitRoot(i)); |
| dimension = dimension.multiply(d); |
| } |
| return dimension; |
| } |
| |
| @Override |
| public UnitConverter getDimensionalTransform() { |
| UnitConverter converter = AbstractConverter.IDENTITY; |
| for (int i = 0; i < this.getUnitCount(); i++) { |
| AbstractUnit<?> unit = (AbstractUnit<?>) this.getUnit(i); |
| UnitConverter cvtr = unit.getDimensionalTransform(); |
| if (!(cvtr.isLinear())) |
| throw new UnsupportedOperationException(cvtr.getClass() + " is non-linear, cannot convert product unit"); |
| if (this.getUnitRoot(i) != 1) |
| throw new UnsupportedOperationException(this + " holds a unit with fractional exponent"); |
| int pow = this.getUnitPow(i); |
| if (pow < 0) { // Negative power. |
| pow = -pow; |
| cvtr = cvtr.inverse(); |
| } |
| for (int j = 0; j < pow; j++) { |
| converter = converter.concatenate(cvtr); |
| } |
| } |
| return converter; |
| } |
| |
| /** |
| * Returns the greatest common divisor (Euclid's algorithm). |
| * |
| * @param m the first number. |
| * @param nn the second number. |
| * @return the greatest common divisor. |
| */ |
| private static int gcd(int m, int n) { |
| if (n == 0) |
| return m; |
| else |
| return gcd(n, m % n); |
| } |
| |
| /** |
| * Inner product element represents a rational power of a single unit. |
| */ |
| private final static class Element implements Serializable { |
| |
| /** |
| * |
| */ |
| private static final long serialVersionUID = 1649532173171667701L; |
| |
| /** |
| * Holds the single unit. |
| */ |
| private final Unit<?> unit; |
| |
| /** |
| * Holds the power exponent. |
| */ |
| private final int pow; |
| |
| /** |
| * Holds the root exponent. |
| */ |
| private final int root; |
| |
| /** |
| * Structural constructor. |
| * |
| * @param unit the unit. |
| * @param pow the power exponent. |
| * @param root the root exponent. |
| */ |
| private Element(Unit<?> unit, int pow, int root) { |
| this.unit = unit; |
| this.pow = pow; |
| this.root = root; |
| } |
| |
| /** |
| * Returns this element's unit. |
| * |
| * @return the single unit. |
| */ |
| public Unit<?> getUnit() { |
| return unit; |
| } |
| |
| /** |
| * Returns the power exponent. The power exponent can be negative but is |
| * always different from zero. |
| * |
| * @return the power exponent of the single unit. |
| */ |
| public int getPow() { |
| return pow; |
| } |
| |
| /** |
| * Returns the root exponent. The root exponent is always greater than |
| * zero. |
| * |
| * @return the root exponent of the single unit. |
| */ |
| public int getRoot() { |
| return root; |
| } |
| } |
| |
| @Override |
| public UnitConverter getConverterToAny(Unit<?> arg0) { |
| if (hasOnlyUnscaledMetricUnits()) // Product of standard units is a standard unit itself. |
| return AbstractConverter.IDENTITY; |
| UnitConverter converter = AbstractConverter.IDENTITY; |
| for (int i = 0; i < elements.length; i++) { |
| Element e = elements[i]; |
| UnitConverter cvtr; |
| try { |
| cvtr = e.unit.getConverterToAny(this); |
| } catch (UnconvertibleException e1) { |
| throw e1; |
| } catch (IncommensurableException e1) { |
| throw new UnsupportedOperationException(e1); |
| } |
| if (!(cvtr.isLinear())) |
| throw new UnsupportedOperationException(e.unit + " is non-linear, cannot convert"); |
| if (e.root != 1) |
| throw new UnsupportedOperationException(e.unit + " holds a base unit with fractional exponent"); |
| int pow = e.pow; |
| if (pow < 0) { // Negative power. |
| pow = -pow; |
| cvtr = cvtr.inverse(); |
| } |
| for (int j = 0; j < pow; j++) { |
| converter = converter.concatenate(cvtr); |
| } |
| } |
| return converter; |
| } |
| |
| @SuppressWarnings("unchecked") |
| @Override |
| protected Unit<Q> toMetric() { |
| if (hasOnlyUnscaledMetricUnits()) |
| return this; |
| Unit<?> systemUnit = AbstractUnit.ONE; |
| for (int i = 0; i < elements.length; i++) { |
| Unit<?> unit = elements[i].unit.getSystemUnit(); |
| unit = unit.pow(elements[i].pow); |
| unit = unit.root(elements[i].root); |
| systemUnit = systemUnit.multiply(unit); |
| } |
| return (Unit<Q>) systemUnit; |
| } |
| |
| @Override |
| public Unit<Q> getSystemUnit() { |
| return toMetric(); |
| } |
| } |