Package org.jscience.mathematics.number

Class FloatingPoint

java.lang.Object
java.lang.Number
org.jscience.mathematics.number.Number<FloatingPoint>
org.jscience.mathematics.number.FloatingPoint
All Implemented Interfaces:
Serializable, Comparable<FloatingPoint>, javolution.lang.Immutable, javolution.lang.Realtime, javolution.lang.ValueType, javolution.xml.XMLSerializable, Field<FloatingPoint>, GroupAdditive<FloatingPoint>, GroupMultiplicative<FloatingPoint>, Ring<FloatingPoint>, Structure<FloatingPoint>
public final class FloatingPoint extends Number<FloatingPoint> implements Field<FloatingPoint>

This class represents a floating point number of arbitrary precision. A floating point number consists of a significand and a decimal exponent: (significand · 10exponent).

Unlike Real numbers, no calculation error is performed on floating point instances but the number of digits used during calculations can be specified (see setDigits(int)). The largest the number of digits, the smallest the numeric error. For example:[code] FloatingPoint two = FloatingPoint.valueOf(2); FloatingPoint.setDigits(30); // 30 digits calculations. System.out.println(two.sqrt()); > 0.141421356237309504880168872420E1 [/code]

Instances of this class are immutable and can be used to find accurate solutions to linear equations with the Matrix class.

See Also:

  • Field Details

    • ZERO

      public static final FloatingPoint ZERO
      The floating point instance representing the additive identity.

    • ONE

      public static final FloatingPoint ONE
      The floating point instance representing the multiplicative identity.

    • NaN

      public static final FloatingPoint NaN
      The Not-a-Number instance (unique).

  • Method Details

    • valueOf

      public static FloatingPoint valueOf(LargeInteger significand, int exponent)
      Returns the floating point number for the specified LargeInteger significand and power of two exponent.
      Parameters:
      significand - the significand value.
      exponent - the power of two exponent.
      Returns:
      (significand · 2exponent

    • valueOf

      public static FloatingPoint valueOf(long significand, int exponent)
      Returns the floating point number for the specified long significand and power of two exponent (convenience method).
      Parameters:
      significand - the significand value.
      exponent - the power of two exponent.
      Returns:
      (significand · 2exponent

    • valueOf

      public static FloatingPoint valueOf(long longValue)
      Returns the floating point number for the specified long value (convenience method).
      Parameters:
      longValue - the long value.
      Returns:
      FloatingPoint.valueOf(longValue, 0)

    • valueOf

      public static FloatingPoint valueOf(double doubleValue)
      Returns the floating point number for the specified double value (convenience method).
      Parameters:
      doubleValue - the double value.
      Returns:
      FloatingPoint.valueOf(longValue, 0)

    • valueOf

      public static FloatingPoint valueOf(CharSequence chars)
      Returns the floating point number for the specified character sequence. The number of digits
      Parameters:
      chars - the character sequence.
      Returns:
      the corresponding FloatingPoint number.

    • getDigits

      public static int getDigits()
      Returns the local number of digits used during calculations (default 20 digits).
      Returns:
      the number of digits.

    • setDigits

      public static void setDigits(int digits)
      Sets the local number of digits to be used during calculations.
      Parameters:
      digits - the number of digits.
      Throws:
      IllegalArgumentException - if digits <= 0

    • getSignificand

      public LargeInteger getSignificand()
      Returns the significand value.
      Returns:
      this floating point significand.

    • getExponent

      public int getExponent()
      Returns the decimal exponent.
      Returns:
      this floating point decimal exponent.

    • round

      public LargeInteger round()
      Returns the closest integer to this floating point number.
      Returns:
      this floating point rounded to the nearest integer.

    • opposite

      public FloatingPoint opposite()
      Returns the opposite of this floating point number.
      Specified by:
      opposite in interface GroupAdditive<FloatingPoint>
      Returns:
      -this.

    • plus

      public FloatingPoint plus(FloatingPoint that)
      Returns the sum of this floating point number with the one specified.
      Specified by:
      plus in interface GroupAdditive<FloatingPoint>
      Parameters:
      that - the floating point number to be added.
      Returns:
      this + that.

    • minus

      public FloatingPoint minus(FloatingPoint that)
      Returns the difference between this FloatingPoint number and the one specified.
      Overrides:
      minus in class Number<FloatingPoint>
      Parameters:
      that - the floating point number to be subtracted.
      Returns:
      this - that.

    • times

      public FloatingPoint times(long multiplier)
      Returns the product of this floating point number with the specified long multiplier.
      Parameters:
      multiplier - the long multiplier.
      Returns:
      this · multiplier.

    • times

      public FloatingPoint times(FloatingPoint that)
      Returns the product of this floating point number with the one specified.
      Specified by:
      times in interface GroupMultiplicative<FloatingPoint>
      Specified by:
      times in interface Ring<FloatingPoint>
      Parameters:
      that - the floating point number multiplier.
      Returns:
      this · that.

    • inverse

      public FloatingPoint inverse()
      Returns the inverse of this floating point number.
      Specified by:
      inverse in interface GroupMultiplicative<FloatingPoint>
      Returns:
      1 / this.
      Throws:
      ArithmeticException - if dividend.isZero()

    • divide

      public FloatingPoint divide(FloatingPoint that)
      Returns this floating point number divided by the one specified.
      Parameters:
      that - the FloatingPoint number divisor.
      Returns:
      this / that.
      Throws:
      ArithmeticException - if that.equals(ZERO)

    • abs

      public FloatingPoint abs()
      Returns the absolute value of this floating point number.
      Returns:
      |this|.

    • sqrt

      public FloatingPoint sqrt()
      Returns the square root of this floating point number.
      Returns:
      the positive square root of this floating point number.

    • isZero

      public boolean isZero()
      Indicates if this floating point number is equal to zero.
      Returns:
      this == 0

    • isPositive

      public boolean isPositive()
      Indicates if this floating point number is greater than zero.
      Returns:
      this > 0

    • isNegative

      public boolean isNegative()
      Indicates if this rational number is less than zero.
      Returns:
      this < 0

    • isNaN

      public boolean isNaN()
      Indicates if this floating point is Not-a-Number.
      Returns:
      true if this number has unbounded value; false otherwise.

    • isLargerThan

      public boolean isLargerThan(FloatingPoint that)
      Compares the absolute value of two FloatingPoint numbers.
      Specified by:
      isLargerThan in class Number<FloatingPoint>
      Parameters:
      that - the FloatingPoint number to be compared with.
      Returns:
      |this| > |that|

    • toText

      public javolution.text.Text toText()
      Returns the decimal text representation of this number.
      Specified by:
      toText in interface javolution.lang.Realtime
      Specified by:
      toText in class Number<FloatingPoint>
      Returns:
      the text representation of this number.

    • equals

      public boolean equals(Object that)
      Compares this floating point number against the specified object.
      Specified by:
      equals in class Number<FloatingPoint>
      Parameters:
      that - the object to compare with.
      Returns:
      true if the objects are the same; false otherwise.

    • hashCode

      public int hashCode()
      Returns the hash code for this floating point number.
      Specified by:
      hashCode in class Number<FloatingPoint>
      Returns:
      the hash code value.

    • longValue

      public long longValue()
      Returns the value of this floating point number as a long.
      Specified by:
      longValue in class Number<FloatingPoint>
      Returns:
      the numeric value represented by this floating point after conversion to type long.

    • doubleValue

      public double doubleValue()
      Returns the value of this floating point number as a double.
      Specified by:
      doubleValue in class Number<FloatingPoint>
      Returns:
      the numeric value represented by this FloatingPoint after conversion to type double.

    • compareTo

      public int compareTo(FloatingPoint that)
      Compares two floating point number numerically.
      Specified by:
      compareTo in interface Comparable<FloatingPoint>
      Specified by:
      compareTo in class Number<FloatingPoint>
      Parameters:
      that - the floating point number to compare with.
      Returns:
      -1, 0 or 1 as this FloatingPoint number is numerically less than, equal to, or greater than that.

    • copy

      public FloatingPoint copy()
      Description copied from class: Number
      Returns a copy of this number allocated by the calling thread (possibly on the stack).
      Specified by:
      copy in interface javolution.lang.ValueType
      Specified by:
      copy in class Number<FloatingPoint>
      Returns:
      an identical and independant copy of this number.