com.perisic.ring
Class DoubleField

java.lang.Object
  com.perisic.ring.Ring
      com.perisic.ring.DoubleField

public class DoubleField
extends Ring

The real numbers. This is a wrapper class for the primitive Java data type double. This class is not yet fully documented, but methods are similar to the the methods of Ring.Z. This class cannot be instantiated as there is no public constructor. Use Ring.R instead.

• Last Change: 13.12.2003: GPL, MC.
• Copyright:(c) Marc Conrad, 2002, 2003
• Email: ring@perisic.com. Please let me know if you use this software.
• WWW: www.ring.perisic.com
• The com.perisic.ring library is distributed under the terms of the GNU Lesser General Public License (LGPL).
• If you require the package under a different licence please contact me.
• disclaimer: The classes are provided "as is". There is no warranty implied by using the com.perisic.ring package.

Version:

0.2

Author:

Marc Conrad

Field Summary

static DoubleField

R

Fields inherited from class com.perisic.ring.Ring

C, F2, Q, Z

Method Summary

RingElt	add(RingElt a, RingElt b) Addition.
boolean	equalZero(RingElt b) true if b == 0.
RingElt	inv(RingElt a) Multiplicative Inverse.
boolean	isField() Returns true.
RingElt	map(double r) Maps a double to this field.
RingElt	map(java.lang.String str) Returns str as a DoubleField.
RingElt	mult(RingElt a, RingElt b) Multiplication.
RingElt	neg(RingElt b) The additive inverse of b.
RingElt	one() The 1 of the field.
static double	toDouble(RingElt b) returns the double value of b.
java.lang.String	toString()
RingElt	zero() The 0 of the field.

Methods inherited from class com.perisic.ring.Ring

div, ediv, eltToString, equal, evaluatePolynomial, gcd, isEuclidian, isUFD, map, map, map, map, mod, pow, pow, sub, tdiv

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

R

public static final DoubleField R

Method Detail

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

Returns:

"R"

isField

public boolean isField()

Returns true. To be honest, DoubleField is of course not a field. It's not even associative concerning addition (the usual problems concerning real arithmetic in a computer). But for our purposes here it seems wise to return true anyway.

Overrides:

isField in class Ring

Returns:

true

add

public RingElt add(RingElt a,
                   RingElt b)

Addition.

Specified by:

add in class Ring

Returns:

a + b.

mult

public RingElt mult(RingElt a,
                    RingElt b)

Multiplication.

Specified by:

mult in class Ring

Returns:

a * b

inv

public RingElt inv(RingElt a)

Multiplicative Inverse.

Overrides:

inv in class Ring

Returns:

a^-1

one

public RingElt one()

The 1 of the field.

Overrides:

one in class Ring

Returns:

1

zero

public RingElt zero()

The 0 of the field.

Specified by:

zero in class Ring

Returns:

0

neg

public RingElt neg(RingElt b)

The additive inverse of b.

Specified by:

neg in class Ring

Returns:

-b

equalZero

public boolean equalZero(RingElt b)

true if b == 0.

Specified by:

equalZero in class Ring

Returns:

b == 0

toDouble

public static double toDouble(RingElt b)

returns the double value of b.

Returns:

the double value of b.

map

public RingElt map(double r)

Maps a double to this field.

Returns:

r as an element of this Field.

map

public RingElt map(java.lang.String str)

Returns str as a DoubleField. Tries first to map str via java.lang.Double.valueOf(java.lang.String).toDouble(). If this fails the Ring.map(java.lang.String) method is called.

Overrides:

map in class Ring

Returns:

str as element of this Field.

See Also:

Double.parseDouble(java.lang.String)., Ring.map(java.lang.String).