HFE
Class Poly4MultiLinear

java.lang.Object
  |
  +--HFE.Poly4MultiLinear

final class Poly4MultiLinear

extends java.lang.Object

This class provides polynomials of degree one in n independent variables. The polynomials are over the finite field F_4 which is provided in the class Field4.

Version:

0.1

Field Summary

private int[]	coeff Coefficients for the variables.
private int	varNum The number of variables in this polynomial.

Constructor Summary

Poly4MultiLinear()
sets all the coefficients to zero assumes that the polynomial has no variables

Poly4MultiLinear(int varNum)
Sets all the coefficients to zero by allocating new memory.

Poly4MultiLinear(int[] inArray)
array2poly(int[])

Poly4MultiLinear(int varNum, int[] inArray)
Creates a new object by using inArray for the coefficients.

Poly4MultiLinear(Poly4MultiLinear father)
Creates a copy from the given polynomial.

Method Summary

void	add(Poly4MultiLinear whom) calculate this += whom as polynomial addition
void	add(Poly4MultiLinear a, Poly4MultiLinear b) calculates this = a + b as polynomial addition
int	apply(int[] values) Evaluate the polynomial using the given value vector The entry value[0] is _not_ uses, value[1] is the first valid entry.
static int	apply(int[] coeffs, int[] values) Evaluate the polynomial using the given value vector and the given coefficient vector.
void	array2poly(int[] inArray) Sets the coefficients using the given coefficient.
int	coeff(int which) Returns the coefficient for a given variable.
int[]	coeffs() returns the coefficient array without copying it.
void	divFactor(int factor) divides all coefficients by the given factor in F_4.
int	giveVarNum() returns the number of variables for that object
void	initMem() Allocates new memory for the coefficients.
boolean	isEqual(Poly4MultiLinear whom) Compares this and whom coefficientwise.
boolean	isZero() Checks if the polynomial is the zero polynomial.
static void	main(java.lang.String[] args) Mainly invoces the testIt() method.
void	mulAdd(int factor, Poly4MultiLinear whom) this += factor*whom.
void	mulFactor(int factor) multiplies all coefficients by the given factor in F_4.
void	setCoeffs(int[] inArray) Sets all the coefficients by the given array.
void	setZero() Sets all the coefficients to zero
void	sub(Poly4MultiLinear whom) calculate this -= whom as polynomial subtraction
void	sub(Poly4MultiLinear a, Poly4MultiLinear b) calculates this = a - b as polynomial subtraction
static void	testIt() Tests the functionality for the whole class.
void	writeString() Writes the polynomial as a string to stdout

Methods inherited from class java.lang.Object

, clone, equals, finalize, getClass, hashCode, notify, notifyAll, registerNatives, toString, wait, wait, wait

Field Detail

varNum

private int varNum

The number of variables in this polynomial.

coeff

private int[] coeff

Coefficients for the variables. The variables are x_1..x_n where n is varNum. Position 0 is for the constant term.

Constructor Detail

Poly4MultiLinear

public Poly4MultiLinear()

sets all the coefficients to zero assumes that the polynomial has no variables

Poly4MultiLinear

public Poly4MultiLinear(int varNum)

Sets all the coefficients to zero by allocating new memory. Assumes that the polynomial has varNum variables.

Parameters:

varNum - number of variables for that polynomial

Poly4MultiLinear

public Poly4MultiLinear(Poly4MultiLinear father)

Creates a copy from the given polynomial. Uses memory copy for the coefficients.

Poly4MultiLinear

public Poly4MultiLinear(int[] inArray)

array2poly(int[])

Poly4MultiLinear

public Poly4MultiLinear(int varNum,
                        int[] inArray)

Creates a new object by using inArray for the coefficients. Does no checking for arguments, no memory copy.

Parameters:

varNum - number of variables for this object

inArray - coefficients for the multivaribale polynomial

Method Detail

coeff

public int coeff(int which)

Returns the coefficient for a given variable. Valid values: 0: constant term, 1..valNum: variable

coeffs

public int[] coeffs()

returns the coefficient array without copying it.

giveVarNum

public int giveVarNum()

returns the number of variables for that object

isEqual

public boolean isEqual(Poly4MultiLinear whom)

Compares this and whom coefficientwise. If the two polynomials have different number of variables they can not be equal.

Returns:

true iff all the coefficients are the same both objects

isZero

public boolean isZero()

Checks if the polynomial is the zero polynomial.

Returns:

true iff all coefficients are zero

setZero

public void setZero()

Sets all the coefficients to zero

initMem

public void initMem()

Allocates new memory for the coefficients. The coefficients are initalized with zero.

setCoeffs

public void setCoeffs(int[] inArray)

Sets all the coefficients by the given array. Does neither memory copy nor argument checking.

array2poly

public void array2poly(int[] inArray)

Sets the coefficients using the given coefficient. Copies the array and checks if the array has the right length.

Throws:

IllegalArgumentException: - array has the wrong length, needs to be (varNum+1)

mulFactor

public void mulFactor(int factor)

multiplies all coefficients by the given factor in F_4.

divFactor

public void divFactor(int factor)

divides all coefficients by the given factor in F_4.

mulAdd

public void mulAdd(int factor,
                   Poly4MultiLinear whom)

this += factor*whom. Multiplies whom with the scalar factor and adds the result to this.

add

public void add(Poly4MultiLinear a,
                Poly4MultiLinear b)

calculates this = a + b as polynomial addition

add

public void add(Poly4MultiLinear whom)

calculate this += whom as polynomial addition

sub

public void sub(Poly4MultiLinear a,
                Poly4MultiLinear b)

calculates this = a - b as polynomial subtraction

sub

public void sub(Poly4MultiLinear whom)

calculate this -= whom as polynomial subtraction

apply

public int apply(int[] values)

Evaluate the polynomial using the given value vector The entry value[0] is _not_ uses, value[1] is the first valid entry.

Parameters:

values - array with varNum+1 entries

Returns:

value of the current polynimial.

apply

public static int apply(int[] coeffs,
                        int[] values)

Evaluate the polynomial using the given value vector and the given coefficient vector. The entry value[0] is _not_ uses, value[1] is the first valid entry.

Parameters:

coeffs - coefficients of a multivariable, linear polynomial

values - values for the variables of the polynomial, value[1] is the value for the first variable, ...

Returns:

value of the current polynimial.

writeString

public void writeString()

Writes the polynomial as a string to stdout

testIt

public static void testIt()

Tests the functionality for the whole class. Reports errors to stdout.

main

public static void main(java.lang.String[] args)

Mainly invoces the testIt() method.