File	Doc	Category	Size	Date	Package
StrictMath.java	API Doc	Java SE 5 API	44283	Fri Aug 26 14:57:04 BST 2005	java.lang

StrictMath

• java.lang.Object

Fields Summary
public static final double	E The double value that is closer than any other to e, the base of the natural logarithms.
public static final double	PI The double value that is closer than any other to pi, the ratio of the circumference of a circle to its diameter.
private static Random	randomNumberGenerator
private static long	negativeZeroFloatBits
private static long	negativeZeroDoubleBits

Constructors Summary
private StrictMath() Don't let anyone instantiate this class.

Methods Summary
public static native double	IEEEremainder(double f1, double f2) Computes the remainder operation on two arguments as prescribed by the IEEE 754 standard. The remainder value is mathematically equal to f1 - f2 × n, where n is the mathematical integer closest to the exact mathematical value of the quotient f1/f2, and if two mathematical integers are equally close to f1/f2, then n is the integer that is even. If the remainder is zero, its sign is the same as the sign of the first argument. Special cases: If either argument is NaN, or the first argument is infinite, or the second argument is positive zero or negative zero, then the result is NaN. If the first argument is finite and the second argument is infinite, then the result is the same as the first argument. param f1 the dividend. param f2 the divisor. return the remainder when f1 is divided by f2.
public static int	abs(int a) Returns the absolute value of an int value.. If the argument is not negative, the argument is returned. If the argument is negative, the negation of the argument is returned. Note that if the argument is equal to the value of Integer.MIN_VALUE, the most negative representable int value, the result is that same value, which is negative. param a the argument whose absolute value is to be determined. return the absolute value of the argument. see java.lang.Integer#MIN_VALUE return (a < 0) ? -a : a;
public static long	abs(long a) Returns the absolute value of a long value. If the argument is not negative, the argument is returned. If the argument is negative, the negation of the argument is returned. Note that if the argument is equal to the value of Long.MIN_VALUE, the most negative representable long value, the result is that same value, which is negative. param a the argument whose absolute value is to be determined. return the absolute value of the argument. see java.lang.Long#MIN_VALUE return (a < 0) ? -a : a;
public static float	abs(float a) Returns the absolute value of a float value. If the argument is not negative, the argument is returned. If the argument is negative, the negation of the argument is returned. Special cases: If the argument is positive zero or negative zero, the result is positive zero. If the argument is infinite, the result is positive infinity. If the argument is NaN, the result is NaN. In other words, the result is the same as the value of the expression: Float.intBitsToFloat(0x7fffffff & Float.floatToIntBits(a)) param a the argument whose absolute value is to be determined return the absolute value of the argument. return (a <= 0.0F) ? 0.0F - a : a;
public static double	abs(double a) Returns the absolute value of a double value. If the argument is not negative, the argument is returned. If the argument is negative, the negation of the argument is returned. Special cases: If the argument is positive zero or negative zero, the result is positive zero. If the argument is infinite, the result is positive infinity. If the argument is NaN, the result is NaN. In other words, the result is the same as the value of the expression: Double.longBitsToDouble((Double.doubleToLongBits(a)<<1)>>>1) param a the argument whose absolute value is to be determined return the absolute value of the argument. return (a <= 0.0D) ? 0.0D - a : a;
public static native double	acos(double a) Returns the arc cosine of an angle, in the range of 0.0 through pi. Special case: If the argument is NaN or its absolute value is greater than 1, then the result is NaN. param a the value whose arc cosine is to be returned. return the arc cosine of the argument.
public static native double	asin(double a) Returns the arc sine of an angle, in the range of -pi/2 through pi/2. Special cases: If the argument is NaN or its absolute value is greater than 1, then the result is NaN. If the argument is zero, then the result is a zero with the same sign as the argument. param a the value whose arc sine is to be returned. return the arc sine of the argument.
public static native double	atan(double a) Returns the arc tangent of an angle, in the range of -pi/2 through pi/2. Special cases: If the argument is NaN, then the result is NaN. If the argument is zero, then the result is a zero with the same sign as the argument. param a the value whose arc tangent is to be returned. return the arc tangent of the argument.
public static native double	atan2(double y, double x) Converts rectangular coordinates (x, y) to polar (r, theta). This method computes the phase theta by computing an arc tangent of y/x in the range of -pi to pi. Special cases: If either argument is NaN, then the result is NaN. If the first argument is positive zero and the second argument is positive, or the first argument is positive and finite and the second argument is positive infinity, then the result is positive zero. If the first argument is negative zero and the second argument is positive, or the first argument is negative and finite and the second argument is positive infinity, then the result is negative zero. If the first argument is positive zero and the second argument is negative, or the first argument is positive and finite and the second argument is negative infinity, then the result is the double value closest to pi. If the first argument is negative zero and the second argument is negative, or the first argument is negative and finite and the second argument is negative infinity, then the result is the double value closest to -pi. If the first argument is positive and the second argument is positive zero or negative zero, or the first argument is positive infinity and the second argument is finite, then the result is the double value closest to pi/2. If the first argument is negative and the second argument is positive zero or negative zero, or the first argument is negative infinity and the second argument is finite, then the result is the double value closest to -pi/2. If both arguments are positive infinity, then the result is the double value closest to pi/4. If the first argument is positive infinity and the second argument is negative infinity, then the result is the double value closest to 3*pi/4. If the first argument is negative infinity and the second argument is positive infinity, then the result is the double value closest to -pi/4. If both arguments are negative infinity, then the result is the double value closest to -3*pi/4. param y the ordinate coordinate param x the abscissa coordinate return the theta component of the point (r, theta) in polar coordinates that corresponds to the point (x, y) in Cartesian coordinates.
public static native double	cbrt(double a) Returns the cube root of a double value. For positive finite x, cbrt(-x) == -cbrt(x); that is, the cube root of a negative value is the negative of the cube root of that value's magnitude. Special cases: If the argument is NaN, then the result is NaN. If the argument is infinite, then the result is an infinity with the same sign as the argument. If the argument is zero, then the result is a zero with the same sign as the argument. param a a value. return the cube root of a. since 1.5
public static native double	ceil(double a) Returns the smallest (closest to negative infinity) double value that is greater than or equal to the argument and is equal to a mathematical integer. Special cases: If the argument value is already equal to a mathematical integer, then the result is the same as the argument. If the argument is NaN or an infinity or positive zero or negative zero, then the result is the same as the argument. If the argument value is less than zero but greater than -1.0, then the result is negative zero. Note that the value of StrictMath.ceil(x) is exactly the value of -StrictMath.floor(-x). param a a value. return the smallest (closest to negative infinity) floating-point value that is greater than or equal to the argument and is equal to a mathematical integer.
public static native double	cos(double a) Returns the trigonometric cosine of an angle. Special cases: If the argument is NaN or an infinity, then the result is NaN. param a an angle, in radians. return the cosine of the argument.
public static native double	cosh(double x) Returns the hyperbolic cosine of a double value. The hyperbolic cosine of x is defined to be (ex + e-x)/2 where e is {@linkplain Math#E Euler's number}. Special cases: If the argument is NaN, then the result is NaN. If the argument is infinite, then the result is positive infinity. If the argument is zero, then the result is 1.0. param x The number whose hyperbolic cosine is to be returned. return The hyperbolic cosine of x. since 1.5
public static native double	exp(double a) Returns Euler's number e raised to the power of a double value. Special cases: If the argument is NaN, the result is NaN. If the argument is positive infinity, then the result is positive infinity. If the argument is negative infinity, then the result is positive zero. param a the exponent to raise e to. return the value ea, where e is the base of the natural logarithms.
public static native double	expm1(double x) Returns ex -1. Note that for values of x near 0, the exact sum of expm1(x) + 1 is much closer to the true result of ex than exp(x). Special cases: If the argument is NaN, the result is NaN. If the argument is positive infinity, then the result is positive infinity. If the argument is negative infinity, then the result is -1.0. If the argument is zero, then the result is a zero with the same sign as the argument. param x the exponent to raise e to in the computation of ex -1. return the value ex - 1.
public static native double	floor(double a) Returns the largest (closest to positive infinity) double value that is less than or equal to the argument and is equal to a mathematical integer. Special cases: If the argument value is already equal to a mathematical integer, then the result is the same as the argument. If the argument is NaN or an infinity or positive zero or negative zero, then the result is the same as the argument. param a a value. return the largest (closest to positive infinity) floating-point value that less than or equal to the argument and is equal to a mathematical integer.
public static native double	hypot(double x, double y) Returns sqrt(x2 +y2) without intermediate overflow or underflow. Special cases: If either argument is infinite, then the result is positive infinity. If either argument is NaN and neither argument is infinite, then the result is NaN. param x a value param y a value return sqrt(x2 +y2) without intermediate overflow or underflow since 1.5
private static synchronized void	initRNG() if (randomNumberGenerator == null) randomNumberGenerator = new Random();
public static native double	log(double a) Returns the natural logarithm (base e) of a double value. Special cases: If the argument is NaN or less than zero, then the result is NaN. If the argument is positive infinity, then the result is positive infinity. If the argument is positive zero or negative zero, then the result is negative infinity. param a a value return the value ln a, the natural logarithm of a.
public static native double	log10(double a) Returns the base 10 logarithm of a double value. Special cases: If the argument is NaN or less than zero, then the result is NaN. If the argument is positive infinity, then the result is positive infinity. If the argument is positive zero or negative zero, then the result is negative infinity. If the argument is equal to 10n for integer n, then the result is n. param a a value return the base 10 logarithm of a. since 1.5
public static native double	log1p(double x) Returns the natural logarithm of the sum of the argument and 1. Note that for small values x, the result of log1p(x) is much closer to the true result of ln(1 + x) than the floating-point evaluation of log(1.0+x). Special cases: If the argument is NaN or less than -1, then the result is NaN. If the argument is positive infinity, then the result is positive infinity. If the argument is negative one, then the result is negative infinity. If the argument is zero, then the result is a zero with the same sign as the argument. param x a value return the value ln(x + 1), the natural log of x + 1
public static int	max(int a, int b) Returns the greater of two int values. That is, the result is the argument closer to the value of Integer.MAX_VALUE. If the arguments have the same value, the result is that same value. param a an argument. param b another argument. return the larger of a and b. see java.lang.Long#MAX_VALUE return (a >= b) ? a : b;
public static long	max(long a, long b) Returns the greater of two long values. That is, the result is the argument closer to the value of Long.MAX_VALUE. If the arguments have the same value, the result is that same value. param a an argument. param b another argument. return the larger of a and b. see java.lang.Long#MAX_VALUE return (a >= b) ? a : b;
public static float	max(float a, float b) Returns the greater of two float values. That is, the result is the argument closer to positive infinity. If the arguments have the same value, the result is that same value. If either value is NaN, then the result is NaN. Unlike the numerical comparison operators, this method considers negative zero to be strictly smaller than positive zero. If one argument is positive zero and the other negative zero, the result is positive zero. param a an argument. param b another argument. return the larger of a and b. if (a != a) return a; // a is NaN if ((a == 0.0f) && (b == 0.0f) && (Float.floatToIntBits(a) == negativeZeroFloatBits)) { return b; } return (a >= b) ? a : b;
public static double	max(double a, double b) Returns the greater of two double values. That is, the result is the argument closer to positive infinity. If the arguments have the same value, the result is that same value. If either value is NaN, then the result is NaN. Unlike the numerical comparison operators, this method considers negative zero to be strictly smaller than positive zero. If one argument is positive zero and the other negative zero, the result is positive zero. param a an argument. param b another argument. return the larger of a and b. if (a != a) return a; // a is NaN if ((a == 0.0d) && (b == 0.0d) && (Double.doubleToLongBits(a) == negativeZeroDoubleBits)) { return b; } return (a >= b) ? a : b;
public static int	min(int a, int b) Returns the smaller of two int values. That is, the result the argument closer to the value of Integer.MIN_VALUE. If the arguments have the same value, the result is that same value. param a an argument. param b another argument. return the smaller of a and b. see java.lang.Long#MIN_VALUE return (a <= b) ? a : b;
public static long	min(long a, long b) Returns the smaller of two long values. That is, the result is the argument closer to the value of Long.MIN_VALUE. If the arguments have the same value, the result is that same value. param a an argument. param b another argument. return the smaller of a and b. see java.lang.Long#MIN_VALUE return (a <= b) ? a : b;
public static float	min(float a, float b) Returns the smaller of two float values. That is, the result is the value closer to negative infinity. If the arguments have the same value, the result is that same value. If either value is NaN, then the result is NaN. Unlike the numerical comparison operators, this method considers negative zero to be strictly smaller than positive zero. If one argument is positive zero and the other is negative zero, the result is negative zero. param a an argument. param b another argument. return the smaller of a and b. if (a != a) return a; // a is NaN if ((a == 0.0f) && (b == 0.0f) && (Float.floatToIntBits(b) == negativeZeroFloatBits)) { return b; } return (a <= b) ? a : b;
public static double	min(double a, double b) Returns the smaller of two double values. That is, the result is the value closer to negative infinity. If the arguments have the same value, the result is that same value. If either value is NaN, then the result is NaN. Unlike the numerical comparison operators, this method considers negative zero to be strictly smaller than positive zero. If one argument is positive zero and the other is negative zero, the result is negative zero. param a an argument. param b another argument. return the smaller of a and b. if (a != a) return a; // a is NaN if ((a == 0.0d) && (b == 0.0d) && (Double.doubleToLongBits(b) == negativeZeroDoubleBits)) { return b; } return (a <= b) ? a : b;
public static native double	pow(double a, double b) Returns the value of the first argument raised to the power of the second argument. Special cases: If the second argument is positive or negative zero, then the result is 1.0. If the second argument is 1.0, then the result is the same as the first argument. If the second argument is NaN, then the result is NaN. If the first argument is NaN and the second argument is nonzero, then the result is NaN. If the absolute value of the first argument is greater than 1 and the second argument is positive infinity, or the absolute value of the first argument is less than 1 and the second argument is negative infinity, then the result is positive infinity. If the absolute value of the first argument is greater than 1 and the second argument is negative infinity, or the absolute value of the first argument is less than 1 and the second argument is positive infinity, then the result is positive zero. If the absolute value of the first argument equals 1 and the second argument is infinite, then the result is NaN. If the first argument is positive zero and the second argument is greater than zero, or the first argument is positive infinity and the second argument is less than zero, then the result is positive zero. If the first argument is positive zero and the second argument is less than zero, or the first argument is positive infinity and the second argument is greater than zero, then the result is positive infinity. If the first argument is negative zero and the second argument is greater than zero but not a finite odd integer, or the first argument is negative infinity and the second argument is less than zero but not a finite odd integer, then the result is positive zero. If the first argument is negative zero and the second argument is a positive finite odd integer, or the first argument is negative infinity and the second argument is a negative finite odd integer, then the result is negative zero. If the first argument is negative zero and the second argument is less than zero but not a finite odd integer, or the first argument is negative infinity and the second argument is greater than zero but not a finite odd integer, then the result is positive infinity. If the first argument is negative zero and the second argument is a negative finite odd integer, or the first argument is negative infinity and the second argument is a positive finite odd integer, then the result is negative infinity. If the first argument is finite and less than zero if the second argument is a finite even integer, the result is equal to the result of raising the absolute value of the first argument to the power of the second argument if the second argument is a finite odd integer, the result is equal to the negative of the result of raising the absolute value of the first argument to the power of the second argument if the second argument is finite and not an integer, then the result is NaN. If both arguments are integers, then the result is exactly equal to the mathematical result of raising the first argument to the power of the second argument if that result can in fact be represented exactly as a double value. (In the foregoing descriptions, a floating-point value is considered to be an integer if and only if it is finite and a fixed point of the method {@link #ceil ceil} or, equivalently, a fixed point of the method {@link #floor floor}. A value is a fixed point of a one-argument method if and only if the result of applying the method to the value is equal to the value.) param a base. param b the exponent. return the value ab.
public static double	random() Returns a double value with a positive sign, greater than or equal to 0.0 and less than 1.0. Returned values are chosen pseudorandomly with (approximately) uniform distribution from that range. When this method is first called, it creates a single new pseudorandom-number generator, exactly as if by the expression new java.util.Random This new pseudorandom-number generator is used thereafter for all calls to this method and is used nowhere else. This method is properly synchronized to allow correct use by more than one thread. However, if many threads need to generate pseudorandom numbers at a great rate, it may reduce contention for each thread to have its own pseudorandom number generator. return a pseudorandom double greater than or equal to 0.0 and less than 1.0. see java.util.Random#nextDouble() if (randomNumberGenerator == null) initRNG(); return randomNumberGenerator.nextDouble();
public static double	rint(double a) Returns the double value that is closest in value to the argument and is equal to a mathematical integer. If two double values that are mathematical integers are equally close to the value of the argument, the result is the integer value that is even. Special cases: If the argument value is already equal to a mathematical integer, then the result is the same as the argument. If the argument is NaN or an infinity or positive zero or negative zero, then the result is the same as the argument. param a a value. return the closest floating-point value to a that is equal to a mathematical integer. author Joseph D. Darcy /* * If the absolute value of a is not less than 2^52, it * is either a finite integer (the double format does not have * enough significand bits for a number that large to have any * fractional portion), an infinity, or a NaN. In any of * these cases, rint of the argument is the argument. * * Otherwise, the sum (twoToThe52 + a ) will properly round * away any fractional portion of a since ulp(twoToThe52) == * 1.0; subtracting out twoToThe52 from this sum will then be * exact and leave the rounded integer portion of a. * * This method does *not* need to be declared strictfp to get * fully reproducible results. Whether or not a method is * declared strictfp can only make a difference in the * returned result if some operation would overflow or * underflow with strictfp semantics. The operation * (twoToThe52 + a ) cannot overflow since large values of a * are screened out; the add cannot underflow since twoToThe52 * is too large. The subtraction ((twoToThe52 + a ) - * twoToThe52) will be exact as discussed above and thus * cannot overflow or meaningfully underflow. Finally, the * last multiply in the return statement is by plus or minus * 1.0, which is exact too. */ double twoToThe52 = (double)(1L << 52); // 2^52 double sign = FpUtils.rawCopySign(1.0, a); // preserve sign info a = Math.abs(a); if (a < twoToThe52) { // E_min <= ilogb(a) <= 51 a = ((twoToThe52 + a ) - twoToThe52); } return sign * a; // restore original sign
public static int	round(float a) Returns the closest int to the argument. The result is rounded to an integer by adding 1/2, taking the floor of the result, and casting the result to type int. In other words, the result is equal to the value of the expression: (int)Math.floor(a + 0.5f) Special cases: If the argument is NaN, the result is 0. If the argument is negative infinity or any value less than or equal to the value of Integer.MIN_VALUE, the result is equal to the value of Integer.MIN_VALUE. If the argument is positive infinity or any value greater than or equal to the value of Integer.MAX_VALUE, the result is equal to the value of Integer.MAX_VALUE. param a a floating-point value to be rounded to an integer. return the value of the argument rounded to the nearest int value. see java.lang.Integer#MAX_VALUE see java.lang.Integer#MIN_VALUE return (int)floor(a + 0.5f);
public static long	round(double a) Returns the closest long to the argument. The result is rounded to an integer by adding 1/2, taking the floor of the result, and casting the result to type long. In other words, the result is equal to the value of the expression: (long)Math.floor(a + 0.5d) Special cases: If the argument is NaN, the result is 0. If the argument is negative infinity or any value less than or equal to the value of Long.MIN_VALUE, the result is equal to the value of Long.MIN_VALUE. If the argument is positive infinity or any value greater than or equal to the value of Long.MAX_VALUE, the result is equal to the value of Long.MAX_VALUE. param a a floating-point value to be rounded to a long. return the value of the argument rounded to the nearest long value. see java.lang.Long#MAX_VALUE see java.lang.Long#MIN_VALUE return (long)floor(a + 0.5d);
public static double	signum(double d) Returns the signum function of the argument; zero if the argument is zero, 1.0 if the argument is greater than zero, -1.0 if the argument is less than zero. Special Cases: If the argument is NaN, then the result is NaN. If the argument is positive zero or negative zero, then the result is the same as the argument. param d the floating-point value whose signum is to be returned return the signum function of the argument author Joseph D. Darcy since 1.5 return sun.misc.FpUtils.signum(d);
public static float	signum(float f) Returns the signum function of the argument; zero if the argument is zero, 1.0f if the argument is greater than zero, -1.0f if the argument is less than zero. Special Cases: If the argument is NaN, then the result is NaN. If the argument is positive zero or negative zero, then the result is the same as the argument. param f the floating-point value whose signum is to be returned return the signum function of the argument author Joseph D. Darcy since 1.5 return sun.misc.FpUtils.signum(f);
public static native double	sin(double a) Returns the trigonometric sine of an angle. Special cases: If the argument is NaN or an infinity, then the result is NaN. If the argument is zero, then the result is a zero with the same sign as the argument. param a an angle, in radians. return the sine of the argument.
public static native double	sinh(double x) Returns the hyperbolic sine of a double value. The hyperbolic sine of x is defined to be (ex - e-x)/2 where e is {@linkplain Math#E Euler's number}. Special cases: If the argument is NaN, then the result is NaN. If the argument is infinite, then the result is an infinity with the same sign as the argument. If the argument is zero, then the result is a zero with the same sign as the argument. param x The number whose hyperbolic sine is to be returned. return The hyperbolic sine of x. since 1.5
public static native double	sqrt(double a) Returns the correctly rounded positive square root of a double value. Special cases: If the argument is NaN or less than zero, then the result is NaN. If the argument is positive infinity, then the result is positive infinity. If the argument is positive zero or negative zero, then the result is the same as the argument. Otherwise, the result is the double value closest to the true mathematical square root of the argument value. param a a value. return the positive square root of a.
public static native double	tan(double a) Returns the trigonometric tangent of an angle. Special cases: If the argument is NaN or an infinity, then the result is NaN. If the argument is zero, then the result is a zero with the same sign as the argument. param a an angle, in radians. return the tangent of the argument.
public static native double	tanh(double x) Returns the hyperbolic tangent of a double value. The hyperbolic tangent of x is defined to be (ex - e-x)/(ex + e-x), in other words, {@linkplain Math#sinh sinh(x)}/{@linkplain Math#cosh cosh(x)}. Note that the absolute value of the exact tanh is always less than 1. Special cases: If the argument is NaN, then the result is NaN. If the argument is zero, then the result is a zero with the same sign as the argument. If the argument is positive infinity, then the result is +1.0. If the argument is negative infinity, then the result is -1.0. param x The number whose hyperbolic tangent is to be returned. return The hyperbolic tangent of x. since 1.5
public static double	toDegrees(double angrad) Converts an angle measured in radians to an approximately equivalent angle measured in degrees. The conversion from radians to degrees is generally inexact; users should not expect cos(toRadians(90.0)) to exactly equal 0.0. param angrad an angle, in radians return the measurement of the angle angrad in degrees. return angrad * 180.0 / PI;
public static double	toRadians(double angdeg) Converts an angle measured in degrees to an approximately equivalent angle measured in radians. The conversion from degrees to radians is generally inexact. param angdeg an angle, in degrees return the measurement of the angle angdeg in radians. return angdeg / 180.0 * PI;
public static double	ulp(double d) Returns the size of an ulp of the argument. An ulp of a double value is the positive distance between this floating-point value and the double value next larger in magnitude. Note that for non-NaN x, ulp(-x) == ulp(x). Special Cases: If the argument is NaN, then the result is NaN. If the argument is positive or negative infinity, then the result is positive infinity. If the argument is positive or negative zero, then the result is Double.MIN_VALUE. If the argument is ±Double.MAX_VALUE, then the result is equal to 2971. param d the floating-point value whose ulp is to be returned return the size of an ulp of the argument author Joseph D. Darcy since 1.5 return sun.misc.FpUtils.ulp(d);
public static float	ulp(float f) Returns the size of an ulp of the argument. An ulp of a float value is the positive distance between this floating-point value and the float value next larger in magnitude. Note that for non-NaN x, ulp(-x) == ulp(x). Special Cases: If the argument is NaN, then the result is NaN. If the argument is positive or negative infinity, then the result is positive infinity. If the argument is positive or negative zero, then the result is Float.MIN_VALUE. If the argument is ±Float.MAX_VALUE, then the result is equal to 2104. param f the floating-point value whose ulp is to be returned return the size of an ulp of the argument author Joseph D. Darcy since 1.5 return sun.misc.FpUtils.ulp(f);