org.genesys.taxonomy.checker

Class MostFrequentKChars

java.lang.Object

org.genesys.taxonomy.checker.MostFrequentKChars

public class MostFrequentKChars
extends Object

Based on pseudocode at https://en.wikipedia.org/wiki/Most_frequent_k_characters and http://rosettacode.org/wiki/Most_frequent_k_chars_distance Does not handle digits [0-9] for obvious reasons.

Constructor Summary

Constructors

Constructor and Description
MostFrequentKChars()

Method Summary

Modifier and Type	Method and Description
static int	getMostFreqKSimilarity(int[] hash1, int[] hash2) Calculate the similarity of the two hashes.
static int	getMostFreqKSimilarity(String hash1, String hash2) Calculate the similarity of the two hashes.
static String	getMostFrequentKHash(String string, int k) Get the hash for an input string with at most K most frequent characters.
static double	mostFreqKSDF(String inputStr1, String inputStr2, int K) Most freq ksdf.
static int	mostFreqKSDF(String inputStr1, String inputStr2, int K, int maxDistance) Wrapper function.
static String	toHashString(int[] h1) Encode a hash array to String.

Methods inherited from class java.lang.Object

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

Constructor Detail

MostFrequentKChars

public MostFrequentKChars()

Method Detail

getMostFrequentKHash

public static String getMostFrequentKHash(String string,
                                          int k)

Get the hash for an input string with at most K most frequent characters.

        String function MostFreqKHashing (String inputString, int K)
                def string outputString
                for each distinct character
                    count occurrence of each character
                for i := 0 to K
                    char c = next most freq ith character  (if two chars have same frequency then get the first occurrence in inputString)
                    int count = number of occurrence of the character
                    append to outputString, c and count
                end for
                return outputString
 

Parameters:

string - the string

k - the k

Returns:

the most frequent k hash

getMostFreqKSimilarity

public static int getMostFreqKSimilarity(String hash1,
                                         String hash2)

Calculate the similarity of the two hashes.

Parameters:

hash1 - the hash1

hash2 - the hash2

Returns:

the most freq k similarity

getMostFreqKSimilarity

public static int getMostFreqKSimilarity(int[] hash1,
                                         int[] hash2)

Calculate the similarity of the two hashes.

                int function MostFreqKSimilarity (String inputStr1, String inputStr2, int limit)
                    def int similarity
                    for each c = next character from inputStr1
                        lookup c in inputStr2
                        if c is null
                             continue
                        // similarity += frequency of c in inputStr1
                        similarity += frequency of c in inputStr1 + frequency of c in inputStr2
                    // return limit - similarity
                    return similarity
 

Parameters:

hash1 - the hash1

hash2 - the hash2

Returns:

the most freq k similarity

mostFreqKSDF

public static int mostFreqKSDF(String inputStr1,
                               String inputStr2,
                               int K,
                               int maxDistance)

Wrapper function.

                int function MostFreqKSDF (string inputStr1, string inputStr2, int K, int maxDistance)
                    return maxDistance - MostFreqKSimilarity(MostFreqKHashing(inputStr1,K), MostFreqKHashing(inputStr2,K))
 

Parameters:

inputStr1 - the input str1

inputStr2 - the input str2

K - the k

maxDistance - the max distance

Returns:

the int

mostFreqKSDF

public static double mostFreqKSDF(String inputStr1,
                                  String inputStr2,
                                  int K)

Most freq ksdf.

Parameters:

inputStr1 - the input str1

inputStr2 - the input str2

K - the k

Returns:

the double

toHashString

public static String toHashString(int[] h1)

Encode a hash array to String.

Parameters:

h1 - hash array as generated

Returns:

String representation of the hash array (e.g. "i3b2")