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CLDR-16329 Review comments: More generic functions for scales, use bi…
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@pedberg-icu
pedberg-icu committed Feb 2, 2024
1 parent 6727644 commit cc887e2
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Showing 2 changed files with 43 additions and 51 deletions.
2 changes: 1 addition & 1 deletion common/dtd/ldmlSupplemental.dtd
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Original file line number Diff line number Diff line change
Expand Up @@ -458,7 +458,7 @@ CLDR data files are interpreted according to the LDML specification (http://unic
<!--@MATCH:regex/[-+*/\._ 0-9a-zA-Z]+-->
<!--@VALUE-->
<!ATTLIST convertUnit special NMTOKEN #IMPLIED >
<!--@MATCH:regex/(100-)?[A-Za-z][-A-Za-z0-9]*-->
<!--@MATCH:regex/[A-Za-z][-A-Za-z0-9]*-->
<!--@VALUE-->
<!ATTLIST convertUnit systems NMTOKENS #IMPLIED >
<!--@MATCH:set/literal/si, si_acceptable, metric, metric_adjacent, ussystem, uksystem, jpsystem, astronomical, person_age, other, prefixable-->
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92 changes: 42 additions & 50 deletions tools/cldr-code/src/main/java/org/unicode/cldr/util/UnitConverter.java
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Original file line number Diff line number Diff line change
Expand Up @@ -242,28 +242,30 @@ public static final class ConversionInfo implements Comparable<ConversionInfo> {
public final Rational factor;
public final Rational offset;
public String special;
public boolean inverse; // only used with special
public boolean specialInverse; // only used with special

static final ConversionInfo IDENTITY = new ConversionInfo(Rational.ONE, Rational.ZERO);

public ConversionInfo(Rational factor, Rational offset) {
this.factor = factor;
this.offset = offset;
this.special = null;
this.inverse = false;
this.specialInverse = false;
}

public ConversionInfo(String special, boolean inverse) {
this.factor = Rational.ZERO; // if ONE it will be treated as a base unit
this.offset = Rational.ZERO;
this.special = special;
this.inverse = inverse;
this.specialInverse = inverse;
}

public Rational convert(Rational source) {
if (special != null) {
if (special.equals("beaufort")) {
return (inverse) ? baseToBeaufort(source) : beaufortToBase(source);
return (specialInverse)
? baseToScale(source, minMetersPerSecForBeaufort)
: scaleToBase(source, minMetersPerSecForBeaufort);
}
return source;
}
Expand All @@ -273,39 +275,19 @@ public Rational convert(Rational source) {
public Rational convertBackwards(Rational source) {
if (special != null) {
if (special.equals("beaufort")) {
return (inverse) ? beaufortToBase(source) : baseToBeaufort(source);
return (specialInverse)
? scaleToBase(source, minMetersPerSecForBeaufort)
: baseToScale(source, minMetersPerSecForBeaufort);
}
return source;
}
return source.subtract(offset).divide(factor);
}

private static final BigInteger BEAUFORT_MAX = BigInteger.valueOf(17);
private static final Rational[] beaufortToMetersPerSec = {
// midRange m/s values to use for different Bft values
// mostly from m/s = 0.836*(B^1.5) but adjust value for Bft 0
Rational.of("0.1"), // 0 Bft
Rational.of("0.8"), // 1
Rational.of("2.4"), // 2
Rational.of("4.3"), // 3
Rational.of("6.7"), // 4
Rational.of("9.3"), // 5
Rational.of("12.3"), // 6
Rational.of("15.5"), // 7
Rational.of("18.9"), // 8
Rational.of("22.6"), // 9
Rational.of("26.4"), // 10
Rational.of("30.5"), // 11
Rational.of("34.8"), // 12
Rational.of("39.2"), // 13
Rational.of("43.8"), // 14
Rational.of("48.6"), // 15
Rational.of("53.5"), // 16
Rational.of("58.6") // 17
};
private static final Rational[] minMetersPerSecForBeaufort = {
// minimum m/s values for each Bft values
// from table in Wikipedia
// minimum m/s values for each Bft value, plus an extra artificial value
// from table in Wikipedia, except for artificial value
// since 0 based, max Beaufort value is thus array dimension minus 2
Rational.of("0.0"), // 0 Bft
Rational.of("0.3"), // 1
Rational.of("1.6"), // 2
Expand All @@ -323,30 +305,40 @@ public Rational convertBackwards(Rational source) {
Rational.of("41.4"), // 14
Rational.of("46.1"), // 15
Rational.of("51.1"), // 16
Rational.of("55.8") // 17
Rational.of("55.8"), // 17
Rational.of("61.4"), // artificial end of range 17 to give reasonable midpoint
};

private Rational beaufortToBase(Rational beaufort) {
BigInteger beaufortRound = beaufort.abs().add(Rational.of(1, 2)).floor();
if (beaufortRound.compareTo(BEAUFORT_MAX) > 0) {
beaufortRound = BEAUFORT_MAX;
private Rational scaleToBase(Rational scaleValue, Rational[] minBaseForScaleValues) {
BigInteger scaleRound = scaleValue.abs().add(Rational.of(1, 2)).floor();
BigInteger scaleMax = BigInteger.valueOf(minBaseForScaleValues.length - 2);
if (scaleRound.compareTo(scaleMax) > 0) {
scaleRound = scaleMax;
}
int beaufortIndex = beaufortRound.intValue();
return beaufortToMetersPerSec[beaufortIndex];
}

private Rational baseToBeaufort(Rational base) {
base = base.abs();
int beaufortIndex = BEAUFORT_MAX.intValue();
while (base.compareTo(minMetersPerSecForBeaufort[beaufortIndex]) < 0) {
beaufortIndex--;
int scaleIndex = scaleRound.intValue();
// Return midpont of range (the final range uses an articial end to produce reasonable
// midpoint)
return minBaseForScaleValues[scaleIndex]
.add(minBaseForScaleValues[scaleIndex + 1])
.divide(Rational.TWO);
}

private Rational baseToScale(Rational baseValue, Rational[] minBaseForScaleValues) {
int scaleIndex = Arrays.binarySearch(minBaseForScaleValues, baseValue.abs());
if (scaleIndex < 0) {
// since out first array entry is 0, this value will always be -2 or less
scaleIndex = -scaleIndex - 2;
}
int scaleMax = minBaseForScaleValues.length - 2;
if (scaleIndex > scaleMax) {
scaleIndex = scaleMax;
}
return Rational.of(beaufortIndex);
return Rational.of(scaleIndex);
}

public ConversionInfo invert() {
if (special != null) {
return new ConversionInfo(special, !inverse);
return new ConversionInfo(special, !specialInverse);
}
Rational factor2 = factor.reciprocal();
Rational offset2 =
Expand All @@ -362,7 +354,7 @@ public String toString() {

public String toString(String unit) {
if (special != null) {
return "special" + (inverse ? "inv" : "") + ":" + special + "(" + unit + ")";
return "special" + (specialInverse ? "inv" : "") + ":" + special + "(" + unit + ")";
}
return factor.toString(FormatStyle.formatted)
+ " * "
Expand All @@ -379,7 +371,7 @@ public String toDecimal() {

public String toDecimal(String unit) {
if (special != null) {
return "special" + (inverse ? "inv" : "") + ":" + special + "(" + unit + ")";
return "special" + (specialInverse ? "inv" : "") + ":" + special + "(" + unit + ")";
}
return factor.toBigDecimal(MathContext.DECIMAL64)
+ " * "
Expand All @@ -403,8 +395,8 @@ public int compareTo(ConversionInfo o) {
return diff;
}
// Among specials with the same name, inverses sort later
if (inverse != o.inverse) {
return (inverse) ? 1 : -1;
if (specialInverse != o.specialInverse) {
return (specialInverse) ? 1 : -1;
}
return 0;
}
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