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Format to 120 line length. 

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/lang/trunk@1606086 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Gary D. Gregory 2014-06-27 13:09:03 +00:00
parent 60b79a9082
commit 8a95db3d42
1 changed files with 78 additions and 92 deletions
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170
src/main/java/org/apache/commons/lang3/math/Fraction.java
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@ -143,8 +143,7 @@ public static Fraction getFraction(int numerator, int denominator) {
throw new ArithmeticException("The denominator must not be zero");
}
if (denominator < 0) {
if (numerator==Integer.MIN_VALUE ||
denominator==Integer.MIN_VALUE) {
if (numerator == Integer.MIN_VALUE || denominator == Integer.MIN_VALUE) {
throw new ArithmeticException("overflow: can't negate");
}
numerator = -numerator;
@ -181,12 +180,11 @@ public static Fraction getFraction(final int whole, final int numerator, final i
}
long numeratorValue;
if (whole < 0) {
numeratorValue = whole * (long)denominator - numerator;
numeratorValue = whole * (long) denominator - numerator;
} else {
numeratorValue = whole * (long)denominator + numerator;
numeratorValue = whole * (long) denominator + numerator;
}
if (numeratorValue < Integer.MIN_VALUE ||
numeratorValue > Integer.MAX_VALUE) {
if (numeratorValue < Integer.MIN_VALUE || numeratorValue > Integer.MAX_VALUE) {
throw new ArithmeticException("Numerator too large to represent as an Integer.");
}
return new Fraction((int) numeratorValue, denominator);
@ -210,16 +208,16 @@ public static Fraction getReducedFraction(int numerator, int denominator) {
if (denominator == 0) {
throw new ArithmeticException("The denominator must not be zero");
}
if (numerator==0) {
if (numerator == 0) {
return ZERO; // normalize zero.
}
// allow 2^k/-2^31 as a valid fraction (where k>0)
if (denominator==Integer.MIN_VALUE && (numerator&1)==0) {
numerator/=2; denominator/=2;
if (denominator == Integer.MIN_VALUE && (numerator & 1) == 0) {
numerator /= 2;
denominator /= 2;
}
if (denominator < 0) {
if (numerator==Integer.MIN_VALUE ||
denominator==Integer.MIN_VALUE) {
if (numerator == Integer.MIN_VALUE || denominator == Integer.MIN_VALUE) {
throw new ArithmeticException("overflow: can't negate");
}
numerator = -numerator;
@ -249,19 +247,18 @@ public static Fraction getReducedFraction(int numerator, int denominator) {
public static Fraction getFraction(double value) {
final int sign = value < 0 ? -1 : 1;
value = Math.abs(value);
if (value > Integer.MAX_VALUE || Double.isNaN(value)) {
throw new ArithmeticException
("The value must not be greater than Integer.MAX_VALUE or NaN");
if (value > Integer.MAX_VALUE || Double.isNaN(value)) {
throw new ArithmeticException("The value must not be greater than Integer.MAX_VALUE or NaN");
}
final int wholeNumber = (int) value;
value -= wholeNumber;
int numer0 = 0; // the pre-previous
int denom0 = 1; // the pre-previous
int numer1 = 1; // the previous
int denom1 = 0; // the previous
int numer2 = 0; // the current, setup in calculation
int denom2 = 0; // the current, setup in calculation
int numer0 = 0; // the pre-previous
int denom0 = 1; // the pre-previous
int numer1 = 1; // the previous
int denom1 = 0; // the previous
int numer2 = 0; // the current, setup in calculation
int denom2 = 0; // the current, setup in calculation
int a1 = (int) value;
int a2 = 0;
double x1 = 1;
@ -271,7 +268,7 @@ public static Fraction getFraction(double value) {
double delta1, delta2 = Double.MAX_VALUE;
double fraction;
int i = 1;
// System.out.println("---");
// System.out.println("---");
do {
delta1 = delta2;
a2 = (int) (x1 / y1);
@ -281,7 +278,7 @@ public static Fraction getFraction(double value) {
denom2 = a1 * denom1 + denom0;
fraction = (double) numer2 / (double) denom2;
delta2 = Math.abs(value - fraction);
// System.out.println(numer2 + " " + denom2 + " " + fraction + " " + delta2 + " " + y1);
// System.out.println(numer2 + " " + denom2 + " " + fraction + " " + delta2 + " " + y1);
a1 = a2;
x1 = x2;
y1 = y2;
@ -290,7 +287,7 @@ public static Fraction getFraction(double value) {
numer1 = numer2;
denom1 = denom2;
i++;
// System.out.println(">>" + delta1 +" "+ delta2+" "+(delta1 > delta2)+" "+i+" "+denom2);
// System.out.println(">>" + delta1 +" "+ delta2+" "+(delta1 > delta2)+" "+i+" "+denom2);
} while (delta1 > delta2 && denom2 <= 10000 && denom2 > 0 && i < 25);
if (i == 25) {
throw new ArithmeticException("Unable to convert double to fraction");
@ -546,16 +543,16 @@ public Fraction pow(final int power) {
} else if (power == 0) {
return ONE;
} else if (power < 0) {
if (power==Integer.MIN_VALUE) { // MIN_VALUE can't be negated.
return this.invert().pow(2).pow(-(power/2));
if (power == Integer.MIN_VALUE) { // MIN_VALUE can't be negated.
return this.invert().pow(2).pow(-(power / 2));
}
return this.invert().pow(-power);
} else {
final Fraction f = this.multiplyBy(this);
if (power % 2 == 0) { // if even...
return f.pow(power/2);
return f.pow(power / 2);
}
return f.pow(power/2).multiplyBy(this);
return f.pow(power / 2).multiplyBy(this);
}
}
@ -577,7 +574,7 @@ private static int greatestCommonDivisor(int u, int v) {
}
return Math.abs(u) + Math.abs(v);
}
//if either operand is abs 1, return 1:
// if either operand is abs 1, return 1:
if (Math.abs(u) == 1 || Math.abs(v) == 1) {
return 1;
}
@ -585,39 +582,45 @@ private static int greatestCommonDivisor(int u, int v) {
// -2^31, while positive numbers can only be as large as 2^31-1
// (i.e. we can't necessarily negate a negative number without
// overflow)
if (u>0) { u=-u; } // make u negative
if (v>0) { v=-v; } // make v negative
if (u > 0) {
u = -u;
} // make u negative
if (v > 0) {
v = -v;
} // make v negative
// B1. [Find power of 2]
int k=0;
while ((u&1)==0 && (v&1)==0 && k<31) { // while u and v are both even...
u/=2; v/=2; k++; // cast out twos.
int k = 0;
while ((u & 1) == 0 && (v & 1) == 0 && k < 31) { // while u and v are both even...
u /= 2;
v /= 2;
k++; // cast out twos.
}
if (k==31) {
if (k == 31) {
throw new ArithmeticException("overflow: gcd is 2^31");
}
// B2. Initialize: u and v have been divided by 2^k and at least
// one is odd.
int t = (u&1)==1 ? v : -(u/2)/*B3*/;
// one is odd.
int t = (u & 1) == 1 ? v : -(u / 2)/* B3 */;
// t negative: u was odd, v may be even (t replaces v)
// t positive: u was even, v is odd (t replaces u)
do {
/* assert u<0 && v<0; */
// B4/B3: cast out twos from t.
while ((t&1)==0) { // while t is even..
t/=2; // cast out twos
while ((t & 1) == 0) { // while t is even..
t /= 2; // cast out twos
}
// B5 [reset max(u,v)]
if (t>0) {
if (t > 0) {
u = -t;
} else {
v = t;
}
// B6/B3. at this point both u and v should be odd.
t = (v - u)/2;
t = (v - u) / 2;
// |u| larger: t positive (replace u)
// |v| larger: t negative (replace v)
} while (t!=0);
return -u*(1<<k); // gcd is u*2^k
} while (t != 0);
return -u * (1 << k); // gcd is u*2^k
}
// Arithmetic
@ -633,12 +636,11 @@ private static int greatestCommonDivisor(int u, int v) {
* an int
*/
private static int mulAndCheck(final int x, final int y) {
final long m = (long)x*(long)y;
if (m < Integer.MIN_VALUE ||
m > Integer.MAX_VALUE) {
final long m = (long) x * (long) y;
if (m < Integer.MIN_VALUE || m > Integer.MAX_VALUE) {
throw new ArithmeticException("overflow: mul");
}
return (int)m;
return (int) m;
}
/**
@ -652,11 +654,11 @@ private static int mulAndCheck(final int x, final int y) {
*/
private static int mulPosAndCheck(final int x, final int y) {
/* assert x>=0 && y>=0; */
final long m = (long)x*(long)y;
final long m = (long) x * (long) y;
if (m > Integer.MAX_VALUE) {
throw new ArithmeticException("overflow: mulPos");
}
return (int)m;
return (int) m;
}
/**
@ -669,12 +671,11 @@ private static int mulPosAndCheck(final int x, final int y) {
* an int
*/
private static int addAndCheck(final int x, final int y) {
final long s = (long)x+(long)y;
if (s < Integer.MIN_VALUE ||
s > Integer.MAX_VALUE) {
final long s = (long) x + (long) y;
if (s < Integer.MIN_VALUE || s > Integer.MAX_VALUE) {
throw new ArithmeticException("overflow: add");
}
return (int)s;
return (int) s;
}
/**
@ -687,12 +688,11 @@ private static int addAndCheck(final int x, final int y) {
* an int
*/
private static int subAndCheck(final int x, final int y) {
final long s = (long)x-(long)y;
if (s < Integer.MIN_VALUE ||
s > Integer.MAX_VALUE) {
final long s = (long) x - (long) y;
if (s < Integer.MIN_VALUE || s > Integer.MAX_VALUE) {
throw new ArithmeticException("overflow: add");
}
return (int)s;
return (int) s;
}
/**
@ -743,40 +743,34 @@ private Fraction addSub(final Fraction fraction, final boolean isAdd) {
}
if (fraction.numerator == 0) {
return this;
}
}
// if denominators are randomly distributed, d1 will be 1 about 61%
// of the time.
final int d1 = greatestCommonDivisor(denominator, fraction.denominator);
if (d1==1) {
if (d1 == 1) {
// result is ( (u*v' +/- u'v) / u'v')
final int uvp = mulAndCheck(numerator, fraction.denominator);
final int upv = mulAndCheck(fraction.numerator, denominator);
return new Fraction
(isAdd ? addAndCheck(uvp, upv) : subAndCheck(uvp, upv),
mulPosAndCheck(denominator, fraction.denominator));
return new Fraction(isAdd ? addAndCheck(uvp, upv) : subAndCheck(uvp, upv), mulPosAndCheck(denominator,
fraction.denominator));
}
// the quantity 't' requires 65 bits of precision; see knuth 4.5.1
// exercise 7. we're going to use a BigInteger.
// exercise 7. we're going to use a BigInteger.
// t = u(v'/d1) +/- v(u'/d1)
final BigInteger uvp = BigInteger.valueOf(numerator)
.multiply(BigInteger.valueOf(fraction.denominator/d1));
final BigInteger upv = BigInteger.valueOf(fraction.numerator)
.multiply(BigInteger.valueOf(denominator/d1));
final BigInteger uvp = BigInteger.valueOf(numerator).multiply(BigInteger.valueOf(fraction.denominator / d1));
final BigInteger upv = BigInteger.valueOf(fraction.numerator).multiply(BigInteger.valueOf(denominator / d1));
final BigInteger t = isAdd ? uvp.add(upv) : uvp.subtract(upv);
// but d2 doesn't need extra precision because
// d2 = gcd(t,d1) = gcd(t mod d1, d1)
final int tmodd1 = t.mod(BigInteger.valueOf(d1)).intValue();
final int d2 = tmodd1==0?d1:greatestCommonDivisor(tmodd1, d1);
final int d2 = tmodd1 == 0 ? d1 : greatestCommonDivisor(tmodd1, d1);
// result is (t/d2) / (u'/d1)(v'/d2)
final BigInteger w = t.divide(BigInteger.valueOf(d2));
if (w.bitLength() > 31) {
throw new ArithmeticException
("overflow: numerator too large after multiply");
throw new ArithmeticException("overflow: numerator too large after multiply");
}
return new Fraction
(w.intValue(),
mulPosAndCheck(denominator/d1, fraction.denominator/d2));
return new Fraction(w.intValue(), mulPosAndCheck(denominator / d1, fraction.denominator / d2));
}
/**
@ -800,9 +794,8 @@ public Fraction multiplyBy(final Fraction fraction) {
// make sure we don't overflow unless the result *must* overflow.
final int d1 = greatestCommonDivisor(numerator, fraction.denominator);
final int d2 = greatestCommonDivisor(fraction.numerator, denominator);
return getReducedFraction
(mulAndCheck(numerator/d1, fraction.numerator/d2),
mulPosAndCheck(denominator/d2, fraction.denominator/d1));
return getReducedFraction(mulAndCheck(numerator / d1, fraction.numerator / d2),
mulPosAndCheck(denominator / d2, fraction.denominator / d1));
}
/**
@ -845,8 +838,7 @@ public boolean equals(final Object obj) {
return false;
}
final Fraction other = (Fraction) obj;
return getNumerator() == other.getNumerator() &&
getDenominator() == other.getDenominator();
return getNumerator() == other.getNumerator() && getDenominator() == other.getDenominator();
}
/**
@ -877,7 +869,7 @@ public int hashCode() {
*/
@Override
public int compareTo(final Fraction other) {
if (this==other) {
if (this == other) {
return 0;
}
if (numerator == other.numerator && denominator == other.denominator) {
@ -906,10 +898,7 @@ public int compareTo(final Fraction other) {
@Override
public String toString() {
if (toString == null) {
toString = new StringBuilder(32)
.append(getNumerator())
.append('/')
.append(getDenominator()).toString();
toString = new StringBuilder(32).append(getNumerator()).append('/').append(getDenominator()).toString();
}
return toString;
}
@ -931,24 +920,21 @@ public String toProperString() {
toProperString = "1";
} else if (numerator == -1 * denominator) {
toProperString = "-1";
} else if ((numerator>0?-numerator:numerator) < -denominator) {
} else if ((numerator > 0 ? -numerator : numerator) < -denominator) {
// note that we do the magnitude comparison test above with
// NEGATIVE (not positive) numbers, since negative numbers
// have a larger range. otherwise numerator==Integer.MIN_VALUE
// have a larger range. otherwise numerator==Integer.MIN_VALUE
// is handled incorrectly.
final int properNumerator = getProperNumerator();
if (properNumerator == 0) {
toProperString = Integer.toString(getProperWhole());
} else {
toProperString = new StringBuilder(32)
.append(getProperWhole()).append(' ')
.append(properNumerator).append('/')
.append(getDenominator()).toString();
toProperString = new StringBuilder(32).append(getProperWhole()).append(' ').append(properNumerator)
.append('/').append(getDenominator()).toString();
}
} else {
toProperString = new StringBuilder(32)
.append(getNumerator()).append('/')
.append(getDenominator()).toString();
toProperString = new StringBuilder(32).append(getNumerator()).append('/').append(getDenominator())
.toString();
}
}
return toProperString;