Class FastMath

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static double E
      Napier's constant e, base of the natural logarithm.
      static double PI
      Archimede's constant PI, ratio of circle circumference to diameter.
    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static double abs​(double x)
      Absolute value.
      static float abs​(float x)
      Absolute value.
      static int abs​(int x)
      Absolute value.
      static long abs​(long x)
      Absolute value.
      static double acos​(double x)
      Compute the arc cosine of a number.
      static double acosh​(double a)
      Compute the inverse hyperbolic cosine of a number.
      static double asin​(double x)
      Compute the arc sine of a number.
      static double asinh​(double a)
      Compute the inverse hyperbolic sine of a number.
      static double atan​(double x)
      Arctangent function
      static double atan2​(double y, double x)
      Two arguments arctangent function
      static double atanh​(double a)
      Compute the inverse hyperbolic tangent of a number.
      static double cbrt​(double x)
      Compute the cubic root of a number.
      static double ceil​(double x)
      Get the smallest whole number larger than x.
      static double copySign​(double magnitude, double sign)
      Returns the first argument with the sign of the second argument.
      static float copySign​(float magnitude, float sign)
      Returns the first argument with the sign of the second argument.
      static double cos​(double x)
      Cosine function
      static double cosh​(double x)
      Compute the hyperbolic cosine of a number.
      static double exp​(double x)
      Exponential function.
      static double expm1​(double x)
      Compute exp(x) - 1
      static double floor​(double x)
      Get the largest whole number smaller than x.
      static int getExponent​(double d)
      Return the exponent of a double number, removing the bias.
      static int getExponent​(float f)
      Return the exponent of a float number, removing the bias.
      static double hypot​(double x, double y)
      Returns the hypotenuse of a triangle with sides x and y - sqrt(x2 +y2)
      avoiding intermediate overflow or underflow.
      static double IEEEremainder​(double dividend, double divisor)
      Computes the remainder as prescribed by the IEEE 754 standard.
      static double log​(double x)
      Natural logarithm.
      static double log10​(double x)
      Compute the base 10 logarithm.
      static double log1p​(double x)
      Compute log(1 + x).
      static double max​(double a, double b)
      Compute the maximum of two values
      static float max​(float a, float b)
      Compute the maximum of two values
      static int max​(int a, int b)
      Compute the maximum of two values
      static long max​(long a, long b)
      Compute the maximum of two values
      static double min​(double a, double b)
      Compute the minimum of two values
      static float min​(float a, float b)
      Compute the minimum of two values
      static int min​(int a, int b)
      Compute the minimum of two values
      static long min​(long a, long b)
      Compute the minimum of two values
      static double nextAfter​(double d, double direction)
      Get the next machine representable number after a number, moving in the direction of another number.
      static float nextAfter​(float f, double direction)
      Get the next machine representable number after a number, moving in the direction of another number.
      static double nextUp​(double a)
      Compute next number towards positive infinity.
      static float nextUp​(float a)
      Compute next number towards positive infinity.
      static double pow​(double x, double y)
      Power function.
      static double random()
      Returns a pseudo-random number between 0.0 and 1.0.
      static double rint​(double x)
      Get the whole number that is the nearest to x, or the even one if x is exactly half way between two integers.
      static long round​(double x)
      Get the closest long to x.
      static int round​(float x)
      Get the closest int to x.
      static double scalb​(double d, int n)
      Multiply a double number by a power of 2.
      static float scalb​(float f, int n)
      Multiply a float number by a power of 2.
      static double signum​(double a)
      Compute the signum of a number.
      static float signum​(float a)
      Compute the signum of a number.
      static double sin​(double x)
      Sine function.
      static double sinh​(double x)
      Compute the hyperbolic sine of a number.
      static double sqrt​(double a)
      Compute the square root of a number.
      static double tan​(double x)
      Tangent function
      static double tanh​(double x)
      Compute the hyperbolic tangent of a number.
      static double toDegrees​(double x)
      Convert radians to degrees, with error of less than 0.5 ULP
      static double toRadians​(double x)
      Convert degrees to radians, with error of less than 0.5 ULP
      static double ulp​(double x)
      Compute least significant bit (Unit in Last Position) for a number.
      static float ulp​(float x)
      Compute least significant bit (Unit in Last Position) for a number.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • PI

        public static final double PI
        Archimede's constant PI, ratio of circle circumference to diameter.
        See Also:
        Constant Field Values
      • E

        public static final double E
        Napier's constant e, base of the natural logarithm.
        See Also:
        Constant Field Values
    • Method Detail

      • sqrt

        public static double sqrt​(double a)
        Compute the square root of a number.

        Note: this implementation currently delegates to Math.sqrt(double)

        Parameters:
        a - number on which evaluation is done
        Returns:
        square root of a
      • cosh

        public static double cosh​(double x)
        Compute the hyperbolic cosine of a number.
        Parameters:
        x - number on which evaluation is done
        Returns:
        hyperbolic cosine of x
      • sinh

        public static double sinh​(double x)
        Compute the hyperbolic sine of a number.
        Parameters:
        x - number on which evaluation is done
        Returns:
        hyperbolic sine of x
      • tanh

        public static double tanh​(double x)
        Compute the hyperbolic tangent of a number.
        Parameters:
        x - number on which evaluation is done
        Returns:
        hyperbolic tangent of x
      • acosh

        public static double acosh​(double a)
        Compute the inverse hyperbolic cosine of a number.
        Parameters:
        a - number on which evaluation is done
        Returns:
        inverse hyperbolic cosine of a
      • asinh

        public static double asinh​(double a)
        Compute the inverse hyperbolic sine of a number.
        Parameters:
        a - number on which evaluation is done
        Returns:
        inverse hyperbolic sine of a
      • atanh

        public static double atanh​(double a)
        Compute the inverse hyperbolic tangent of a number.
        Parameters:
        a - number on which evaluation is done
        Returns:
        inverse hyperbolic tangent of a
      • signum

        public static double signum​(double a)
        Compute the signum of a number. The signum is -1 for negative numbers, +1 for positive numbers and 0 otherwise
        Parameters:
        a - number on which evaluation is done
        Returns:
        -1.0, -0.0, +0.0, +1.0 or NaN depending on sign of a
      • signum

        public static float signum​(float a)
        Compute the signum of a number. The signum is -1 for negative numbers, +1 for positive numbers and 0 otherwise
        Parameters:
        a - number on which evaluation is done
        Returns:
        -1.0, -0.0, +0.0, +1.0 or NaN depending on sign of a
      • nextUp

        public static double nextUp​(double a)
        Compute next number towards positive infinity.
        Parameters:
        a - number to which neighbor should be computed
        Returns:
        neighbor of a towards positive infinity
      • nextUp

        public static float nextUp​(float a)
        Compute next number towards positive infinity.
        Parameters:
        a - number to which neighbor should be computed
        Returns:
        neighbor of a towards positive infinity
      • random

        public static double random()
        Returns a pseudo-random number between 0.0 and 1.0.

        Note: this implementation currently delegates to Math.random()

        Returns:
        a random number between 0.0 and 1.0
      • exp

        public static double exp​(double x)
        Exponential function. Computes exp(x), function result is nearly rounded. It will be correctly rounded to the theoretical value for 99.9% of input values, otherwise it will have a 1 UPL error. Method: Lookup intVal = exp(int(x)) Lookup fracVal = exp(int(x-int(x) / 1024.0) * 1024.0 ); Compute z as the exponential of the remaining bits by a polynomial minus one exp(x) = intVal * fracVal * (1 + z) Accuracy: Calculation is done with 63 bits of precision, so result should be correctly rounded for 99.9% of input values, with less than 1 ULP error otherwise.
        Parameters:
        x - a double
        Returns:
        double ex
      • expm1

        public static double expm1​(double x)
        Compute exp(x) - 1
        Parameters:
        x - number to compute shifted exponential
        Returns:
        exp(x) - 1
      • log

        public static double log​(double x)
        Natural logarithm.
        Parameters:
        x - a double
        Returns:
        log(x)
      • log1p

        public static double log1p​(double x)
        Compute log(1 + x).
        Parameters:
        x - a number
        Returns:
        log(1 + x)
      • log10

        public static double log10​(double x)
        Compute the base 10 logarithm.
        Parameters:
        x - a number
        Returns:
        log10(x)
      • pow

        public static double pow​(double x,
                                 double y)
        Power function. Compute x^y.
        Parameters:
        x - a double
        y - a double
        Returns:
        double
      • sin

        public static double sin​(double x)
        Sine function.
        Parameters:
        x - a number
        Returns:
        sin(x)
      • cos

        public static double cos​(double x)
        Cosine function
        Parameters:
        x - a number
        Returns:
        cos(x)
      • tan

        public static double tan​(double x)
        Tangent function
        Parameters:
        x - a number
        Returns:
        tan(x)
      • atan

        public static double atan​(double x)
        Arctangent function
        Parameters:
        x - a number
        Returns:
        atan(x)
      • atan2

        public static double atan2​(double y,
                                   double x)
        Two arguments arctangent function
        Parameters:
        y - ordinate
        x - abscissa
        Returns:
        phase angle of point (x,y) between -PI and PI
      • asin

        public static double asin​(double x)
        Compute the arc sine of a number.
        Parameters:
        x - number on which evaluation is done
        Returns:
        arc sine of x
      • acos

        public static double acos​(double x)
        Compute the arc cosine of a number.
        Parameters:
        x - number on which evaluation is done
        Returns:
        arc cosine of x
      • cbrt

        public static double cbrt​(double x)
        Compute the cubic root of a number.
        Parameters:
        x - number on which evaluation is done
        Returns:
        cubic root of x
      • toRadians

        public static double toRadians​(double x)
        Convert degrees to radians, with error of less than 0.5 ULP
        Parameters:
        x - angle in degrees
        Returns:
        x converted into radians
      • toDegrees

        public static double toDegrees​(double x)
        Convert radians to degrees, with error of less than 0.5 ULP
        Parameters:
        x - angle in radians
        Returns:
        x converted into degrees
      • abs

        public static int abs​(int x)
        Absolute value.
        Parameters:
        x - number from which absolute value is requested
        Returns:
        abs(x)
      • abs

        public static long abs​(long x)
        Absolute value.
        Parameters:
        x - number from which absolute value is requested
        Returns:
        abs(x)
      • abs

        public static float abs​(float x)
        Absolute value.
        Parameters:
        x - number from which absolute value is requested
        Returns:
        abs(x)
      • abs

        public static double abs​(double x)
        Absolute value.
        Parameters:
        x - number from which absolute value is requested
        Returns:
        abs(x)
      • ulp

        public static double ulp​(double x)
        Compute least significant bit (Unit in Last Position) for a number.
        Parameters:
        x - number from which ulp is requested
        Returns:
        ulp(x)
      • ulp

        public static float ulp​(float x)
        Compute least significant bit (Unit in Last Position) for a number.
        Parameters:
        x - number from which ulp is requested
        Returns:
        ulp(x)
      • scalb

        public static double scalb​(double d,
                                   int n)
        Multiply a double number by a power of 2.
        Parameters:
        d - number to multiply
        n - power of 2
        Returns:
        d × 2n
      • scalb

        public static float scalb​(float f,
                                  int n)
        Multiply a float number by a power of 2.
        Parameters:
        f - number to multiply
        n - power of 2
        Returns:
        f × 2n
      • nextAfter

        public static double nextAfter​(double d,
                                       double direction)
        Get the next machine representable number after a number, moving in the direction of another number.

        The ordering is as follows (increasing):

        • -INFINITY
        • -MAX_VALUE
        • -MIN_VALUE
        • -0.0
        • +0.0
        • +MIN_VALUE
        • +MAX_VALUE
        • +INFINITY
        • If arguments compare equal, then the second argument is returned.

          If direction is greater than d, the smallest machine representable number strictly greater than d is returned; if less, then the largest representable number strictly less than d is returned.

          If d is infinite and direction does not bring it back to finite numbers, it is returned unchanged.

        Parameters:
        d - base number
        direction - (the only important thing is whether direction is greater or smaller than d)
        Returns:
        the next machine representable number in the specified direction
      • nextAfter

        public static float nextAfter​(float f,
                                      double direction)
        Get the next machine representable number after a number, moving in the direction of another number.

        The ordering is as follows (increasing):

        • -INFINITY
        • -MAX_VALUE
        • -MIN_VALUE
        • -0.0
        • +0.0
        • +MIN_VALUE
        • +MAX_VALUE
        • +INFINITY
        • If arguments compare equal, then the second argument is returned.

          If direction is greater than f, the smallest machine representable number strictly greater than f is returned; if less, then the largest representable number strictly less than f is returned.

          If f is infinite and direction does not bring it back to finite numbers, it is returned unchanged.

        Parameters:
        f - base number
        direction - (the only important thing is whether direction is greater or smaller than f)
        Returns:
        the next machine representable number in the specified direction
      • floor

        public static double floor​(double x)
        Get the largest whole number smaller than x.
        Parameters:
        x - number from which floor is requested
        Returns:
        a double number f such that f is an integer f <= x < f + 1.0
      • ceil

        public static double ceil​(double x)
        Get the smallest whole number larger than x.
        Parameters:
        x - number from which ceil is requested
        Returns:
        a double number c such that c is an integer c - 1.0 < x <= c
      • rint

        public static double rint​(double x)
        Get the whole number that is the nearest to x, or the even one if x is exactly half way between two integers.
        Parameters:
        x - number from which nearest whole number is requested
        Returns:
        a double number r such that r is an integer r - 0.5 <= x <= r + 0.5
      • round

        public static long round​(double x)
        Get the closest long to x.
        Parameters:
        x - number from which closest long is requested
        Returns:
        closest long to x
      • round

        public static int round​(float x)
        Get the closest int to x.
        Parameters:
        x - number from which closest int is requested
        Returns:
        closest int to x
      • min

        public static int min​(int a,
                              int b)
        Compute the minimum of two values
        Parameters:
        a - first value
        b - second value
        Returns:
        a if a is lesser or equal to b, b otherwise
      • min

        public static long min​(long a,
                               long b)
        Compute the minimum of two values
        Parameters:
        a - first value
        b - second value
        Returns:
        a if a is lesser or equal to b, b otherwise
      • min

        public static float min​(float a,
                                float b)
        Compute the minimum of two values
        Parameters:
        a - first value
        b - second value
        Returns:
        a if a is lesser or equal to b, b otherwise
      • min

        public static double min​(double a,
                                 double b)
        Compute the minimum of two values
        Parameters:
        a - first value
        b - second value
        Returns:
        a if a is lesser or equal to b, b otherwise
      • max

        public static int max​(int a,
                              int b)
        Compute the maximum of two values
        Parameters:
        a - first value
        b - second value
        Returns:
        b if a is lesser or equal to b, a otherwise
      • max

        public static long max​(long a,
                               long b)
        Compute the maximum of two values
        Parameters:
        a - first value
        b - second value
        Returns:
        b if a is lesser or equal to b, a otherwise
      • max

        public static float max​(float a,
                                float b)
        Compute the maximum of two values
        Parameters:
        a - first value
        b - second value
        Returns:
        b if a is lesser or equal to b, a otherwise
      • max

        public static double max​(double a,
                                 double b)
        Compute the maximum of two values
        Parameters:
        a - first value
        b - second value
        Returns:
        b if a is lesser or equal to b, a otherwise
      • hypot

        public static double hypot​(double x,
                                   double y)
        Returns the hypotenuse of a triangle with sides x and y - sqrt(x2 +y2)
        avoiding intermediate overflow or underflow.
        • If either argument is infinite, then the result is positive infinity.
        • else, if either argument is NaN then the result is NaN.
        Parameters:
        x - a value
        y - a value
        Returns:
        sqrt(x2 +y2)
      • IEEEremainder

        public static double IEEEremainder​(double dividend,
                                           double divisor)
        Computes the remainder as prescribed by the IEEE 754 standard. The remainder value is mathematically equal to x - y*n where n is the mathematical integer closest to the exact mathematical value of the quotient x/y. If two mathematical integers are equally close to x/y then n is the integer that is even.

        • If either operand is NaN, the result is NaN.
        • If the result is not NaN, the sign of the result equals the sign of the dividend.
        • If the dividend is an infinity, or the divisor is a zero, or both, the result is NaN.
        • If the dividend is finite and the divisor is an infinity, the result equals the dividend.
        • If the dividend is a zero and the divisor is finite, the result equals the dividend.

        Note: this implementation currently delegates to StrictMath.IEEEremainder(double, double)

        Parameters:
        dividend - the number to be divided
        divisor - the number by which to divide
        Returns:
        the remainder, rounded
      • copySign

        public static double copySign​(double magnitude,
                                      double sign)
        Returns the first argument with the sign of the second argument. A NaN sign argument is treated as positive.
        Parameters:
        magnitude - the value to return
        sign - the sign for the returned value
        Returns:
        the magnitude with the same sign as the sign argument
      • copySign

        public static float copySign​(float magnitude,
                                     float sign)
        Returns the first argument with the sign of the second argument. A NaN sign argument is treated as positive.
        Parameters:
        magnitude - the value to return
        sign - the sign for the returned value
        Returns:
        the magnitude with the same sign as the sign argument
      • getExponent

        public static int getExponent​(double d)
        Return the exponent of a double number, removing the bias.

        For double numbers of the form 2x, the unbiased exponent is exactly x.

        Parameters:
        d - number from which exponent is requested
        Returns:
        exponent for d in IEEE754 representation, without bias
      • getExponent

        public static int getExponent​(float f)
        Return the exponent of a float number, removing the bias.

        For float numbers of the form 2x, the unbiased exponent is exactly x.

        Parameters:
        f - number from which exponent is requested
        Returns:
        exponent for d in IEEE754 representation, without bias