From e2f141427e441daa9d6be0ba8a30b844ca4391e0 Mon Sep 17 00:00:00 2001 From: Adrien Hopkins Date: Thu, 27 Aug 2020 08:07:21 -0500 Subject: Added the ability to restrict conversion to customary->metric. --- src/org/unitConverter/unit/SI.java | 59 ++++---- src/org/unitConverter/unit/Unit.java | 250 ++++++++++++++++++------------- src/org/unitConverter/unit/UnitTest.java | 12 ++ 3 files changed, 192 insertions(+), 129 deletions(-) (limited to 'src/org/unitConverter/unit') diff --git a/src/org/unitConverter/unit/SI.java b/src/org/unitConverter/unit/SI.java index a4fbd5f..f36cf28 100644 --- a/src/org/unitConverter/unit/SI.java +++ b/src/org/unitConverter/unit/SI.java @@ -17,6 +17,7 @@ package org.unitConverter.unit; import java.util.Arrays; +import java.util.Collections; import java.util.HashSet; import java.util.Set; @@ -91,6 +92,9 @@ public final class SI { public static final BaseUnit DOLLAR = BaseUnit .valueOf(BaseDimensions.CURRENCY, "dollar", "$"); + public static final Set BASE_UNITS = setOf(METRE, KILOGRAM, + SECOND, AMPERE, KELVIN, MOLE, CANDELA, BIT); + // You may NOT get SI.BaseUnits instances! private BaseUnits() { throw new AssertionError(); @@ -210,6 +214,7 @@ public final class SI { /// The units of the SI public static final LinearUnit ONE = LinearUnit .valueOf(ObjectProduct.empty(), 1); + public static final LinearUnit METRE = BaseUnits.METRE.asLinearUnit() .withName(NameSymbol.of("metre", "m", "meter")); public static final LinearUnit KILOGRAM = BaseUnits.KILOGRAM.asLinearUnit() @@ -228,10 +233,10 @@ public final class SI { .withName(NameSymbol.of("bit", "b")); public static final LinearUnit DOLLAR = BaseUnits.DOLLAR.asLinearUnit() .withName(NameSymbol.of("dollar", "$")); - // Non-base units public static final LinearUnit RADIAN = METRE.dividedBy(METRE) .withName(NameSymbol.of("radian", "rad")); + public static final LinearUnit STERADIAN = RADIAN.times(RADIAN) .withName(NameSymbol.of("steradian", "sr")); public static final LinearUnit HERTZ = ONE.dividedBy(SECOND) @@ -277,10 +282,10 @@ public final class SI { // for dose equivalent public static final LinearUnit KATAL = MOLE.dividedBy(SECOND) .withName(NameSymbol.of("katal", "kat")); - // common derived units included for convenience public static final LinearUnit GRAM = KILOGRAM.dividedBy(1000) .withName(NameSymbol.of("gram", "g")); + public static final LinearUnit SQUARE_METRE = METRE.toExponent(2) .withName(NameSymbol.of("square metre", "m^2", "square meter", "metre squared", "meter squared")); @@ -290,12 +295,12 @@ public final class SI { public static final LinearUnit METRE_PER_SECOND = METRE.dividedBy(SECOND) .withName( NameSymbol.of("metre per second", "m/s", "meter per second")); - // Non-SI units included for convenience public static final Unit CELSIUS = Unit .fromConversionFunctions(KELVIN.getBase(), tempK -> tempK - 273.15, tempC -> tempC + 273.15) .withName(NameSymbol.of("degree Celsius", "\u00B0C")); + public static final LinearUnit MINUTE = SECOND.times(60) .withName(NameSymbol.of("minute", "min")); public static final LinearUnit HOUR = MINUTE.times(60) @@ -324,7 +329,7 @@ public final class SI { .withName(NameSymbol.of("tonne", "t", "metric ton")); public static final LinearUnit DALTON = KILOGRAM.times(1.660539040e-27) .withName(NameSymbol.of("dalton", "Da", "atomic unit", "u")); // approximate - // value + // value public static final LinearUnit ELECTRONVOLT = JOULE.times(1.602176634e-19) .withName(NameSymbol.of("electron volt", "eV")); public static final LinearUnit BYTE = BIT.times(8) @@ -339,11 +344,11 @@ public final class SI { .fromConversionFunctions(ONE.getBase(), pr -> 10 * Math.log10(pr), dB -> Math.pow(10, dB / 10)) .withName(NameSymbol.of("decibel", "dB")); - /// The prefixes of the SI // expanding decimal prefixes public static final UnitPrefix KILO = UnitPrefix.valueOf(1e3) .withName(NameSymbol.of("kilo", "k", "K")); + public static final UnitPrefix MEGA = UnitPrefix.valueOf(1e6) .withName(NameSymbol.of("mega", "M")); public static final UnitPrefix GIGA = UnitPrefix.valueOf(1e9) @@ -358,10 +363,10 @@ public final class SI { .withName(NameSymbol.of("zetta", "Z")); public static final UnitPrefix YOTTA = UnitPrefix.valueOf(1e24) .withName(NameSymbol.of("yotta", "Y")); - // contracting decimal prefixes public static final UnitPrefix MILLI = UnitPrefix.valueOf(1e-3) .withName(NameSymbol.of("milli", "m")); + public static final UnitPrefix MICRO = UnitPrefix.valueOf(1e-6) .withName(NameSymbol.of("micro", "\u03BC", "u")); // mu public static final UnitPrefix NANO = UnitPrefix.valueOf(1e-9) @@ -376,10 +381,10 @@ public final class SI { .withName(NameSymbol.of("zepto", "z")); public static final UnitPrefix YOCTO = UnitPrefix.valueOf(1e-24) .withName(NameSymbol.of("yocto", "y")); - // prefixes that don't match the pattern of thousands public static final UnitPrefix DEKA = UnitPrefix.valueOf(1e1) .withName(NameSymbol.of("deka", "da", "deca", "D")); + public static final UnitPrefix HECTO = UnitPrefix.valueOf(1e2) .withName(NameSymbol.of("hecto", "h", "H", "hekto")); public static final UnitPrefix DECI = UnitPrefix.valueOf(1e-1) @@ -398,25 +403,29 @@ public final class SI { .withName(NameSymbol.of("pebi", "Pi")); public static final UnitPrefix EXBI = PEBI.times(1024) .withName(NameSymbol.of("exbi", "Ei")); - // sets of prefixes - public static final Set ALL_PREFIXES = new HashSet<>( - Arrays.asList(DEKA, HECTO, KILO, MEGA, GIGA, TERA, PETA, EXA, ZETTA, - YOTTA, DECI, CENTI, MILLI, MICRO, NANO, PICO, FEMTO, ATTO, ZEPTO, - YOCTO, KIBI, MEBI, GIBI, TEBI, PEBI, EXBI)); - public static final Set DECIMAL_PREFIXES = new HashSet<>( - Arrays.asList(DEKA, HECTO, KILO, MEGA, GIGA, TERA, PETA, EXA, ZETTA, - YOTTA, DECI, CENTI, MILLI, MICRO, NANO, PICO, FEMTO, ATTO, ZEPTO, - YOCTO)); - public static final Set THOUSAND_PREFIXES = new HashSet<>( - Arrays.asList(KILO, MEGA, GIGA, TERA, PETA, EXA, ZETTA, YOTTA, MILLI, - MICRO, NANO, PICO, FEMTO, ATTO, ZEPTO, YOCTO)); - public static final Set MAGNIFYING_PREFIXES = new HashSet<>( - Arrays.asList(DEKA, HECTO, KILO, MEGA, GIGA, TERA, PETA, EXA, ZETTA, - YOTTA, KIBI, MEBI, GIBI, TEBI, PEBI, EXBI)); - public static final Set REDUCING_PREFIXES = new HashSet<>( - Arrays.asList(DECI, CENTI, MILLI, MICRO, NANO, PICO, FEMTO, ATTO, - ZEPTO, YOCTO)); + public static final Set ALL_PREFIXES = setOf(DEKA, HECTO, KILO, + MEGA, GIGA, TERA, PETA, EXA, ZETTA, YOTTA, DECI, CENTI, MILLI, MICRO, + NANO, PICO, FEMTO, ATTO, ZEPTO, YOCTO, KIBI, MEBI, GIBI, TEBI, PEBI, + EXBI); + + public static final Set DECIMAL_PREFIXES = setOf(DEKA, HECTO, + KILO, MEGA, GIGA, TERA, PETA, EXA, ZETTA, YOTTA, DECI, CENTI, MILLI, + MICRO, NANO, PICO, FEMTO, ATTO, ZEPTO, YOCTO); + public static final Set THOUSAND_PREFIXES = setOf(KILO, MEGA, + GIGA, TERA, PETA, EXA, ZETTA, YOTTA, MILLI, MICRO, NANO, PICO, FEMTO, + ATTO, ZEPTO, YOCTO); + public static final Set MAGNIFYING_PREFIXES = setOf(DEKA, HECTO, + KILO, MEGA, GIGA, TERA, PETA, EXA, ZETTA, YOTTA, KIBI, MEBI, GIBI, + TEBI, PEBI, EXBI); + public static final Set REDUCING_PREFIXES = setOf(DECI, CENTI, + MILLI, MICRO, NANO, PICO, FEMTO, ATTO, ZEPTO, YOCTO); + + // this method just calls Arrays.asList, which is itself safe. + @SafeVarargs + private static final Set setOf(T... args) { + return Collections.unmodifiableSet(new HashSet<>(Arrays.asList(args))); + } // You may NOT get SI instances! private SI() { diff --git a/src/org/unitConverter/unit/Unit.java b/src/org/unitConverter/unit/Unit.java index 35b32fc..eb9b000 100644 --- a/src/org/unitConverter/unit/Unit.java +++ b/src/org/unitConverter/unit/Unit.java @@ -25,6 +25,7 @@ import java.util.Optional; import java.util.Set; import java.util.function.DoubleUnaryOperator; +import org.unitConverter.math.DecimalComparison; import org.unitConverter.math.ObjectProduct; /** @@ -35,209 +36,211 @@ import org.unitConverter.math.ObjectProduct; */ public abstract class Unit { /** - * Returns a unit from its base and the functions it uses to convert to and from its base. + * Returns a unit from its base and the functions it uses to convert to and + * from its base. * *

- * For example, to get a unit representing the degree Celsius, the following code can be used: + * For example, to get a unit representing the degree Celsius, the following + * code can be used: * * {@code Unit.fromConversionFunctions(SI.KELVIN, tempK -> tempK - 273.15, tempC -> tempC + 273.15);} *

* - * @param base - * unit's base - * @param converterFrom - * function that accepts a value expressed in the unit's base and returns that value expressed in this - * unit. - * @param converterTo - * function that accepts a value expressed in the unit and returns that value expressed in the unit's - * base. + * @param base unit's base + * @param converterFrom function that accepts a value expressed in the unit's + * base and returns that value expressed in this unit. + * @param converterTo function that accepts a value expressed in the unit + * and returns that value expressed in the unit's base. * @return a unit that uses the provided functions to convert. * @since 2019-05-22 - * @throws NullPointerException - * if any argument is null + * @throws NullPointerException if any argument is null */ - public static final Unit fromConversionFunctions(final ObjectProduct base, - final DoubleUnaryOperator converterFrom, final DoubleUnaryOperator converterTo) { + public static final Unit fromConversionFunctions( + final ObjectProduct base, + final DoubleUnaryOperator converterFrom, + final DoubleUnaryOperator converterTo) { return new FunctionalUnit(base, converterFrom, converterTo); } - + /** - * Returns a unit from its base and the functions it uses to convert to and from its base. + * Returns a unit from its base and the functions it uses to convert to and + * from its base. * *

- * For example, to get a unit representing the degree Celsius, the following code can be used: + * For example, to get a unit representing the degree Celsius, the following + * code can be used: * * {@code Unit.fromConversionFunctions(SI.KELVIN, tempK -> tempK - 273.15, tempC -> tempC + 273.15);} *

* - * @param base - * unit's base - * @param converterFrom - * function that accepts a value expressed in the unit's base and returns that value expressed in this - * unit. - * @param converterTo - * function that accepts a value expressed in the unit and returns that value expressed in the unit's - * base. - * @param ns - * names and symbol of unit + * @param base unit's base + * @param converterFrom function that accepts a value expressed in the unit's + * base and returns that value expressed in this unit. + * @param converterTo function that accepts a value expressed in the unit + * and returns that value expressed in the unit's base. + * @param ns names and symbol of unit * @return a unit that uses the provided functions to convert. * @since 2019-05-22 - * @throws NullPointerException - * if any argument is null + * @throws NullPointerException if any argument is null */ - public static final Unit fromConversionFunctions(final ObjectProduct base, - final DoubleUnaryOperator converterFrom, final DoubleUnaryOperator converterTo, final NameSymbol ns) { + public static final Unit fromConversionFunctions( + final ObjectProduct base, + final DoubleUnaryOperator converterFrom, + final DoubleUnaryOperator converterTo, final NameSymbol ns) { return new FunctionalUnit(base, converterFrom, converterTo, ns); } - + /** * The combination of units that this unit is based on. * * @since 2019-10-16 */ private final ObjectProduct unitBase; - + /** * The primary name used by this unit. */ private final Optional primaryName; - + /** * A short symbol used to represent this unit. */ private final Optional symbol; - + /** * A set of any additional names and/or spellings that the unit uses. */ private final Set otherNames; - + /** * Cache storing the result of getDimension() * * @since 2019-10-16 */ private transient ObjectProduct dimension = null; - + /** * Creates the {@code AbstractUnit}. * - * @param unitBase - * base of unit - * @param ns - * names and symbol of unit + * @param unitBase base of unit + * @param ns names and symbol of unit * @since 2019-10-16 - * @throws NullPointerException - * if unitBase or ns is null + * @throws NullPointerException if unitBase or ns is null */ protected Unit(final ObjectProduct unitBase, final NameSymbol ns) { - this.unitBase = Objects.requireNonNull(unitBase, "unitBase must not be null."); - this.primaryName = Objects.requireNonNull(ns, "ns must not be null.").getPrimaryName(); + this.unitBase = Objects.requireNonNull(unitBase, + "unitBase must not be null."); + this.primaryName = Objects.requireNonNull(ns, "ns must not be null.") + .getPrimaryName(); this.symbol = ns.getSymbol(); this.otherNames = ns.getOtherNames(); } - + /** * A constructor that constructs {@code BaseUnit} instances. * * @since 2019-10-16 */ - Unit(final String primaryName, final String symbol, final Set otherNames) { + Unit(final String primaryName, final String symbol, + final Set otherNames) { if (this instanceof BaseUnit) { this.unitBase = ObjectProduct.oneOf((BaseUnit) this); } else throw new AssertionError(); this.primaryName = Optional.of(primaryName); this.symbol = Optional.of(symbol); - this.otherNames = Collections.unmodifiableSet( - new HashSet<>(Objects.requireNonNull(otherNames, "additionalNames must not be null."))); + this.otherNames = Collections.unmodifiableSet(new HashSet<>(Objects + .requireNonNull(otherNames, "additionalNames must not be null."))); } - + /** - * Checks if a value expressed in this unit can be converted to a value expressed in {@code other} + * Checks if a value expressed in this unit can be converted to a value + * expressed in {@code other} * - * @param other - * unit to test with + * @param other unit to test with * @return true if the units are compatible * @since 2019-01-13 * @since v0.1.0 - * @throws NullPointerException - * if other is null + * @throws NullPointerException if other is null */ public final boolean canConvertTo(final Unit other) { Objects.requireNonNull(other, "other must not be null."); return Objects.equals(this.getBase(), other.getBase()); } - + /** - * Converts from a value expressed in this unit's base unit to a value expressed in this unit. + * Converts from a value expressed in this unit's base unit to a value + * expressed in this unit. *

- * This must be the inverse of {@code convertToBase}, so {@code convertFromBase(convertToBase(value))} must be equal - * to {@code value} for any value, ignoring precision loss by roundoff error. + * This must be the inverse of {@code convertToBase}, so + * {@code convertFromBase(convertToBase(value))} must be equal to + * {@code value} for any value, ignoring precision loss by roundoff error. *

*

- * If this unit is a base unit, this method should return {@code value}. + * If this unit is a base unit, this method should return + * {@code value}. *

* - * @implSpec This method is used by {@link #convertTo}, and its behaviour affects the behaviour of - * {@code convertTo}. + * @implSpec This method is used by {@link #convertTo}, and its behaviour + * affects the behaviour of {@code convertTo}. * - * @param value - * value expressed in base unit + * @param value value expressed in base unit * @return value expressed in this unit * @since 2018-12-22 * @since v0.1.0 */ protected abstract double convertFromBase(double value); - + /** - * Converts a value expressed in this unit to a value expressed in {@code other}. + * Converts a value expressed in this unit to a value expressed in + * {@code other}. * * @implSpec If unit conversion is possible, this implementation returns - * {@code other.convertFromBase(this.convertToBase(value))}. Therefore, overriding either of those methods - * will change the output of this method. + * {@code other.convertFromBase(this.convertToBase(value))}. + * Therefore, overriding either of those methods will change the + * output of this method. * - * @param other - * unit to convert to - * @param value - * value to convert + * @param other unit to convert to + * @param value value to convert * @return converted value * @since 2019-05-22 - * @throws IllegalArgumentException - * if {@code other} is incompatible for conversion with this unit (as tested by - * {@link Unit#canConvertTo}). - * @throws NullPointerException - * if other is null + * @throws IllegalArgumentException if {@code other} is incompatible for + * conversion with this unit (as tested by + * {@link Unit#canConvertTo}). + * @throws NullPointerException if other is null */ public final double convertTo(final Unit other, final double value) { Objects.requireNonNull(other, "other must not be null."); if (this.canConvertTo(other)) return other.convertFromBase(this.convertToBase(value)); else - throw new IllegalArgumentException(String.format("Cannot convert from %s to %s.", this, other)); + throw new IllegalArgumentException( + String.format("Cannot convert from %s to %s.", this, other)); } - + /** - * Converts from a value expressed in this unit to a value expressed in this unit's base unit. + * Converts from a value expressed in this unit to a value expressed in this + * unit's base unit. *

- * This must be the inverse of {@code convertFromBase}, so {@code convertToBase(convertFromBase(value))} must be - * equal to {@code value} for any value, ignoring precision loss by roundoff error. + * This must be the inverse of {@code convertFromBase}, so + * {@code convertToBase(convertFromBase(value))} must be equal to + * {@code value} for any value, ignoring precision loss by roundoff error. *

*

- * If this unit is a base unit, this method should return {@code value}. + * If this unit is a base unit, this method should return + * {@code value}. *

* - * @implSpec This method is used by {@link #convertTo}, and its behaviour affects the behaviour of - * {@code convertTo}. + * @implSpec This method is used by {@link #convertTo}, and its behaviour + * affects the behaviour of {@code convertTo}. * - * @param value - * value expressed in this unit + * @param value value expressed in this unit * @return value expressed in base unit * @since 2018-12-22 * @since v0.1.0 */ protected abstract double convertToBase(double value); - + /** * @return combination of units that this unit is based on * @since 2018-12-22 @@ -246,7 +249,7 @@ public abstract class Unit { public final ObjectProduct getBase() { return this.unitBase; } - + /** * @return dimension measured by this unit * @since 2018-12-22 @@ -256,16 +259,16 @@ public abstract class Unit { if (this.dimension == null) { final Map mapping = this.unitBase.exponentMap(); final Map dimensionMap = new HashMap<>(); - + for (final BaseUnit key : mapping.keySet()) { dimensionMap.put(key.getBaseDimension(), mapping.get(key)); } - + this.dimension = ObjectProduct.fromExponentMapping(dimensionMap); } return this.dimension; } - + /** * @return additionalNames * @since 2019-10-21 @@ -273,7 +276,7 @@ public abstract class Unit { public final Set getOtherNames() { return this.otherNames; } - + /** * @return primaryName * @since 2019-10-21 @@ -281,7 +284,7 @@ public abstract class Unit { public final Optional getPrimaryName() { return this.primaryName; } - + /** * @return symbol * @since 2019-10-21 @@ -289,25 +292,64 @@ public abstract class Unit { public final Optional getSymbol() { return this.symbol; } - + + /** + * Returns true iff this unit is metric. + *

+ * "Metric" is defined by three conditions: + *

    + *
  • Must be an instance of {@link LinearUnit}.
    • + *
  • Must be based on the SI base units (as determined by getBase())
    • + *
  • The conversion factor must be a power of 10.
    • + *
+ *

+ * Note that this definition excludes some units that many would consider + * "metric", such as the degree Celsius (fails the first condition), + * calories, minutes and hours (fail the third condition). + *

+ * All SI units (as designated by the BIPM) except the degree Celsius are + * considered "metric" by this definition. + * + * @since 2020-08-27 + */ + public final boolean isMetric() { + // first condition - check that it is a linear unit + if (!(this instanceof LinearUnit)) + return false; + final LinearUnit linear = (LinearUnit) this; + + // second condition - check that + for (final BaseUnit b : linear.getBase().getBaseSet()) { + if (!SI.BaseUnits.BASE_UNITS.contains(b)) + return false; + } + + // third condition - check that conversion factor is a power of 10 + return DecimalComparison + .equals(Math.log10(linear.getConversionFactor()) % 1.0, 0); + } + @Override public String toString() { return this.getPrimaryName().orElse("Unnamed unit") - + (this.getSymbol().isPresent() ? String.format(" (%s)", this.getSymbol().get()) : "") - + ", derived from " + this.getBase().toString(u -> u.getSymbol().get()) - + (this.getOtherNames().isEmpty() ? "" : ", also called " + String.join(", ", this.getOtherNames())); + + (this.getSymbol().isPresent() + ? String.format(" (%s)", this.getSymbol().get()) + : "") + + ", derived from " + + this.getBase().toString(u -> u.getSymbol().get()) + + (this.getOtherNames().isEmpty() ? "" + : ", also called " + String.join(", ", this.getOtherNames())); } - + /** - * @param ns - * name(s) and symbol to use + * @param ns name(s) and symbol to use * @return a copy of this unit with provided name(s) and symbol * @since 2019-10-21 - * @throws NullPointerException - * if ns is null + * @throws NullPointerException if ns is null */ public Unit withName(final NameSymbol ns) { - return fromConversionFunctions(this.getBase(), this::convertFromBase, this::convertToBase, + return fromConversionFunctions(this.getBase(), this::convertFromBase, + this::convertToBase, Objects.requireNonNull(ns, "ns must not be null.")); } } diff --git a/src/org/unitConverter/unit/UnitTest.java b/src/org/unitConverter/unit/UnitTest.java index 2cf3126..ff83805 100644 --- a/src/org/unitConverter/unit/UnitTest.java +++ b/src/org/unitConverter/unit/UnitTest.java @@ -16,6 +16,7 @@ */ package org.unitConverter.unit; +import static org.junit.Assert.assertFalse; import static org.junit.jupiter.api.Assertions.assertEquals; import static org.junit.jupiter.api.Assertions.assertThrows; import static org.junit.jupiter.api.Assertions.assertTrue; @@ -104,6 +105,17 @@ class UnitTest { assertEquals(metre, meter); } + @Test + public void testIsMetric() { + final Unit metre = SI.METRE; + final Unit megasecond = SI.SECOND.withPrefix(SI.MEGA); + final Unit hour = SI.HOUR; + + assertTrue(metre.isMetric()); + assertTrue(megasecond.isMetric()); + assertFalse(hour.isMetric()); + } + @Test public void testMultiplicationAndDivision() { // test unit-times-unit multiplication -- cgit v1.2.3