hcrypto.analyzer.tool
Class TextStatistics

java.lang.Object
  hcrypto.analyzer.tool.TextStatistics

All Implemented Interfaces:

Analyzer

public class TextStatistics
extends java.lang.Object
implements Analyzer

Defines a SINGLETON object that is designed to compute and store various useful statistics for a give text. The text is represted as a String.

Field Summary

int	alphabeticsCount
int	charCount
double	coincidenceIndex
static int	digram_chars
static int[][]	digram_data
static double[]	englishFrequency
static double	KAPPA_P
static double	KAPPA_R

Fields inherited from interface hcrypto.analyzer.Analyzer

DECIPHER_LIMIT

Constructor Summary

TextStatistics()

TextStatistics(java.lang.String text)

TextStatistics(java.lang.String text, boolean stripString)

Method Summary

void	calcStatistics()
static double	chiSquare(int[] expected, int[] observed) Static methods for Computing chi square statistic
int	getCharCount() returns the total number of characters in the text
double	getCoincidenceIndex()
static double	getEnglishFrequency(char ch) Static Utility Methods Used by Analyzers
int	getFrequency(char inChar) returns the frequency of its char parameter
java.lang.String	getFrequencyReport() returns a 2-D table of frequencies
FrequencyTable	getFrequencyTable()
static int	getIndexOfMinimum(double[] a)
java.lang.String	getKHighestFreqChar(int k) returns the the kth highest frequency character
java.lang.String	getReport()
void	print()
static java.lang.String	removeDuplicates(java.lang.String s)
static java.lang.String	removeNonAlphabetics(java.lang.String s, Alphabet a) This method removes all characters not in the alphabet from the string.
void	run()
void	setup(java.lang.String text) Part of Analyzer interface
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

KAPPA_R

public static final double KAPPA_R

See Also:

Constant Field Values

KAPPA_P

public static final double KAPPA_P

See Also:

Constant Field Values

englishFrequency

public static final double[] englishFrequency

digram_chars

public static final int digram_chars

See Also:

Constant Field Values

digram_data

public static final int[][] digram_data

charCount

public int charCount

alphabeticsCount

public int alphabeticsCount

coincidenceIndex

public double coincidenceIndex

Constructor Detail

TextStatistics

public TextStatistics()

TextStatistics

public TextStatistics(java.lang.String text)

TextStatistics

public TextStatistics(java.lang.String text,
                      boolean stripString)

Method Detail

getEnglishFrequency

public static double getEnglishFrequency(char ch)

Static Utility Methods Used by Analyzers

chiSquare

public static double chiSquare(int[] expected,
                               int[] observed)

Static methods for Computing chi square statistic

getIndexOfMinimum

public static int getIndexOfMinimum(double[] a)

removeNonAlphabetics

public static java.lang.String removeNonAlphabetics(java.lang.String s,
                                                    Alphabet a)

This method removes all characters not in the alphabet from the string.

removeDuplicates

public static java.lang.String removeDuplicates(java.lang.String s)

setup

public void setup(java.lang.String text)

Part of Analyzer interface

Specified by:

setup in interface Analyzer

run

public void run()

Specified by:

run in interface Analyzer

getReport

public java.lang.String getReport()

Specified by:

getReport in interface Analyzer

print

public void print()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

calcStatistics

public void calcStatistics()

getCoincidenceIndex

public double getCoincidenceIndex()

getFrequencyTable

public FrequencyTable getFrequencyTable()

getCharCount

public int getCharCount()

returns the total number of characters in the text

getFrequency

public int getFrequency(char inChar)

returns the frequency of its char parameter

getKHighestFreqChar

public java.lang.String getKHighestFreqChar(int k)

returns the the kth highest frequency character

getFrequencyReport

public java.lang.String getFrequencyReport()

returns a 2-D table of frequencies