com.perisic.ring
Class RationalField

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

public class RationalField
extends Ring

The field Q of rational numbers. The only instance of this field is Ring.Q

• Last Change: 13.12.2003: GPL.
• 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

Fields inherited from class com.perisic.ring.Ring

C, F2, R, Z

Method Summary

RingElt	add(RingElt a, RingElt b) Returns a + b.
RingElt	construct(java.math.BigInteger numerator, java.math.BigInteger denominator) Returns numerator/denominator.
static java.math.BigInteger	denominatorToBigInteger(RingElt b) Returns the denominator s if b = r/s.
boolean	equalZero(RingElt b) True if b == 0.
RingElt	inv(RingElt b) Returns the multiplicative inverse.
boolean	isField() Returns true.
static boolean	isIntegral(RingElt b) true if denominator of b equals 1.
RingElt	map(RingElt a) Maps Ring.Z elements and into this.
RingElt	map(java.lang.String a) Maps the String a of the form xxxxx/yyyyy and xxxxxx into this field.
RingElt	mult(RingElt a, RingElt b) Returns a * b.
RingElt	neg(RingElt b) Returns -b.
static java.math.BigInteger	numeratorToBigInteger(RingElt b) Returns the numerator r if b = r/s.
RingElt	one() Returns 1.
java.lang.String	toString() Returns "Q".
RingElt	zero() Returns 0.

Methods inherited from class com.perisic.ring.Ring

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

Methods inherited from class java.lang.Object

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

Method Detail

isField

public boolean isField()

Returns true.

Overrides:

isField in class Ring

add

public RingElt add(RingElt a,
                   RingElt b)

Returns a + b.

Specified by:

add in class Ring

mult

public RingElt mult(RingElt a,
                    RingElt b)

Returns a * b.

Specified by:

mult in class Ring

one

public RingElt one()

Returns 1.

Overrides:

one in class Ring

zero

public RingElt zero()

Returns 0.

Specified by:

zero in class Ring

inv

public RingElt inv(RingElt b)

Returns the multiplicative inverse.

Overrides:

inv in class Ring

neg

public RingElt neg(RingElt b)

Returns -b.

Specified by:

neg in class Ring

equalZero

public boolean equalZero(RingElt b)

True if b == 0.

Specified by:

equalZero in class Ring

map

public RingElt map(RingElt a)

Maps Ring.Z elements and into this.

Overrides:

map in class Ring

toString

public java.lang.String toString()

Returns "Q".

Overrides:

toString in class java.lang.Object

isIntegral

public static boolean isIntegral(RingElt b)

true if denominator of b equals 1.

numeratorToBigInteger

public static java.math.BigInteger numeratorToBigInteger(RingElt b)

Returns the numerator r if b = r/s.

denominatorToBigInteger

public static java.math.BigInteger denominatorToBigInteger(RingElt b)

Returns the denominator s if b = r/s.

construct

public RingElt construct(java.math.BigInteger numerator,
                         java.math.BigInteger denominator)

Returns numerator/denominator.

map

public RingElt map(java.lang.String a)

Maps the String a of the form xxxxx/yyyyy and xxxxxx into this field.

Overrides:

map in class Ring

Throws:

RingException - if the String is not of the form above.