shh.csparse
Class SparseEltZInt

Object
  SparseElt
      SparseEltEuc
          SparseEltZ
              SparseEltZInt

All Implemented Interfaces:

Comparable

public final class SparseEltZInt

extends SparseEltZ

Elements of a sparse vector over Z, using int to store the values. If an operation would cause the ints to overflow, we automatically return a larger type of SparseEltZ.

Author:

Mark McConnell

Field Summary

protected int

val The value of this entry in a sparse vector.

Fields inherited from class SparseEltZ

NEG_ONE, ONE, ZERO

Fields inherited from class SparseElt

INDEX_SORTER

Method Summary

SparseEltZ	abs() Returns a SparseEltZ whose value is the absolute value of the value of this, and whose index is that of this.
SparseElt	add(SparseElt y) Returns a SparseElt whose value is the sum of the values in this and y, and whose index is that of this.
int	bitLength() If the value is a BigInteger, returns its BigInteger.bitLength(); if the value is stored in a primitive type, returns the bit length of the type.
int	compareTo(Object o) Compares SparseEltZs by < on the values.
SparseElt	copy(int indexOfCopy) Returns a SparseElt with the same value as this, and with index indexOfCopy.
SparseEltField	copyMod(int p, BigInteger pBig) Returns this mod p, preserving the index.
SparseEltZ[]	divideAndRemainder(SparseEltZ y) Computes this/y and returns a two-element array with values quotient and remainder.
boolean	divides(SparseElt y) Whether the value of this divides the value of y; that is, whether there is an x such that x * this = y.
Number	eucNorm() Returns the absolute value of the value, as a BigInteger.
String	getPrintValue() Returns the value in human-readable form.
BigInteger	getValueAsBigInteger() Returns the value as a BigInteger.
double	getValueAsDouble() Returns the value as a double.
int	getValueAsInt() Coerces the value into an int and returns it.
boolean	isNegOne() Whether the value is -1.
boolean	isOne() Whether the value is one.
boolean	isZero() Whether the value is zero.
SparseElt	multiply(int newIndex, SparseElt y) Returns a SparseElt with index newIndex and whose value is the product of the values in this and y.
SparseElt	negate() Returns a SparseElt whose value is the negative of the value of this, and whose index is that of this.
SparseEltEuc	negClosestQuotient(SparseEltEuc y) Negative of the closest quotient: returns q such that q * y + this is as small as possible for eucNorm().
int	signum() Returns -1, 0, or 1 as the value is negative, zero, or positive.
SparseElt	subtract(SparseElt y) Returns a SparseElt whose value is (value of this) minus (value of y), and whose index is that of this.

Methods inherited from class SparseEltZ

getEucNormComparator, getNegOne, getOne, getZero, hashCode, isEqualValue, makeInstance, makeInstance

Methods inherited from class SparseElt

equals, getIndex, multiply, toString

Methods inherited from class Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

val

protected int val

The value of this entry in a sparse vector.

Method Detail

abs

public SparseEltZ abs()

Description copied from class: SparseEltZ

Returns a SparseEltZ whose value is the absolute value of the value of this, and whose index is that of this.

Specified by:

abs in class SparseEltZ

add

public SparseElt add(SparseElt y)

Description copied from class: SparseElt

Returns a SparseElt whose value is the sum of the values in this and y, and whose index is that of this.

Specified by:

add in class SparseElt

bitLength

public final int bitLength()

Description copied from class: SparseElt

If the value is a BigInteger, returns its BigInteger.bitLength(); if the value is stored in a primitive type, returns the bit length of the type.

Specified by:

bitLength in class SparseElt

compareTo

public int compareTo(Object o)

Description copied from class: SparseEltZ

Compares SparseEltZs by < on the values. Use SparseElt.INDEX_SORTER to compare on the indices.

Specified by:

compareTo in interface Comparable

Specified by:

compareTo in class SparseEltZ

copy

public SparseElt copy(int indexOfCopy)

Description copied from class: SparseElt

Returns a SparseElt with the same value as this, and with index indexOfCopy.

Specified by:

copy in class SparseElt

copyMod

public SparseEltField copyMod(int p,
                              BigInteger pBig)

Description copied from class: SparseEltZ

Returns this mod p, preserving the index. Returns null if the value mod p is 0.

Specified by:

copyMod in class SparseEltZ

Parameters:

p - A prime. The user should check it with SparseEltModp.checkP(int).

pBig - p as a BigInteger.

divideAndRemainder

public SparseEltZ[] divideAndRemainder(SparseEltZ y)

Description copied from class: SparseEltZ

Computes this/y and returns a two-element array with values quotient and remainder. Each index is the index of this.

Specified by:

divideAndRemainder in class SparseEltZ

divides

public boolean divides(SparseElt y)

Description copied from class: SparseElt

Whether the value of this divides the value of y; that is, whether there is an x such that x * this = y.

Specified by:

divides in class SparseElt

eucNorm

public Number eucNorm()

Returns the absolute value of the value, as a BigInteger.

Specified by:

eucNorm in class SparseEltEuc

getPrintValue

public String getPrintValue()

Description copied from class: SparseElt

Returns the value in human-readable form.

Specified by:

getPrintValue in class SparseElt

getValueAsDouble

public double getValueAsDouble()

Description copied from class: SparseEltZ

Returns the value as a double.

Specified by:

getValueAsDouble in class SparseEltZ

getValueAsInt

public int getValueAsInt()

Description copied from class: SparseEltZ

Coerces the value into an int and returns it. In other words, returns the value modulo 2³².

Specified by:

getValueAsInt in class SparseEltZ

getValueAsBigInteger

public BigInteger getValueAsBigInteger()

Description copied from class: SparseEltZ

Returns the value as a BigInteger. In principle, this is the only accurate way to get the value, but it may consume memory unnecessarily if this is not a SparseEltZBig. Compare SparseEltZ.getValueAsInt().

Specified by:

getValueAsBigInteger in class SparseEltZ

isNegOne

public boolean isNegOne()

Description copied from class: SparseElt

Whether the value is -1.

Specified by:

isNegOne in class SparseElt

isOne

public boolean isOne()

Description copied from class: SparseElt

Whether the value is one.

Specified by:

isOne in class SparseElt

isZero

public boolean isZero()

Description copied from class: SparseElt

Whether the value is zero.

Specified by:

isZero in class SparseElt

multiply

public SparseElt multiply(int newIndex,
                          SparseElt y)

Description copied from class: SparseElt

Returns a SparseElt with index newIndex and whose value is the product of the values in this and y.

Specified by:

multiply in class SparseElt

negate

public SparseElt negate()

Description copied from class: SparseElt

Returns a SparseElt whose value is the negative of the value of this, and whose index is that of this.

Specified by:

negate in class SparseElt

negClosestQuotient

public SparseEltEuc negClosestQuotient(SparseEltEuc y)

Description copied from class: SparseEltEuc

Negative of the closest quotient: returns q such that q * y + this is as small as possible for SparseEltEuc.eucNorm(). In other words, returns -this/y rounded off to the nearest element of D. The index is that of this.

Specified by:

negClosestQuotient in class SparseEltEuc

signum

public final int signum()

Description copied from class: SparseEltZ

Returns -1, 0, or 1 as the value is negative, zero, or positive.

Specified by:

signum in class SparseEltZ

subtract

public SparseElt subtract(SparseElt y)

Description copied from class: SparseElt

Returns a SparseElt whose value is (value of this) minus (value of y), and whose index is that of this.

Specified by:

subtract in class SparseElt