Binary Cosine Cofficient
- by hairyyak
I was given the following forumulae for calculating this
sim=|QnD| / v|Q|v|D|
I went ahed and implemented a class to compare strings consisting of a series of words
#pragma once
#include <vector>
#include <string>
#include <iostream>
#include <vector>
using namespace std;
class StringSet
{
public:
StringSet(void);
StringSet( const string the_strings[], const int no_of_strings);
~StringSet(void);
StringSet( const vector<string> the_strings);
void add_string( const string the_string);
bool remove_string( const string the_string);
void clear_set(void);
int no_of_strings(void) const;
friend ostream& operator <<(ostream& outs, StringSet& the_strings);
friend StringSet operator *(const StringSet& first, const StringSet& second);
friend StringSet operator +(const StringSet& first, const StringSet& second);
double binary_coefficient( const StringSet& the_second_set);
private:
vector<string> set;
};
#include "StdAfx.h"
#include "StringSet.h"
#include <iterator>
#include <algorithm>
#include <stdexcept>
#include <iostream>
#include <cmath>
StringSet::StringSet(void)
{
}
StringSet::~StringSet(void)
{
}
StringSet::StringSet( const vector<string> the_strings)
{
set = the_strings;
}
StringSet::StringSet( const string the_strings[], const int no_of_strings)
{
copy( the_strings, &the_strings[no_of_strings], back_inserter(set));
}
void StringSet::add_string( const string the_string)
{
try
{
if( find( set.begin(), set.end(), the_string) == set.end())
{
set.push_back(the_string);
}
else
{
//String is already in the set.
throw domain_error("String is already in the set");
}
}
catch( domain_error e)
{
cout << e.what();
exit(1);
}
}
bool StringSet::remove_string( const string the_string)
{
//Found the occurrence of the string. return it an iterator pointing to it.
vector<string>::iterator iter;
if( ( iter = find( set.begin(), set.end(), the_string) ) != set.end())
{
set.erase(iter);
return true;
}
return false;
}
void StringSet::clear_set(void)
{
set.clear();
}
int StringSet::no_of_strings(void) const
{
return set.size();
}
ostream& operator <<(ostream& outs, StringSet& the_strings)
{
vector<string>::const_iterator const_iter = the_strings.set.begin();
for( ; const_iter != the_strings.set.end(); const_iter++)
{
cout << *const_iter << " ";
}
cout << endl;
return outs;
}
//This function returns the union of the two string sets.
StringSet operator *(const StringSet& first, const StringSet& second)
{
vector<string> new_string_set;
new_string_set = first.set;
for( unsigned int i = 0; i < second.set.size(); i++)
{
vector<string>::const_iterator const_iter = find(new_string_set.begin(), new_string_set.end(), second.set[i]);
//String is new - include it.
if( const_iter == new_string_set.end() )
{
new_string_set.push_back(second.set[i]);
}
}
StringSet the_set(new_string_set);
return the_set;
}
//This method returns the intersection of the two string sets.
StringSet operator +(const StringSet& first, const StringSet& second)
{
//For each string in the first string look though the second and see if
//there is a matching pair, in which case include the string in the set.
vector<string> new_string_set;
vector<string>::const_iterator const_iter = first.set.begin();
for ( ; const_iter != first.set.end(); ++const_iter)
{
//Then search through the entire second string to see if
//there is a duplicate.
vector<string>::const_iterator const_iter2 = second.set.begin();
for( ; const_iter2 != second.set.end(); const_iter2++)
{
if( *const_iter == *const_iter2 )
{
new_string_set.push_back(*const_iter);
}
}
}
StringSet new_set(new_string_set);
return new_set;
}
double StringSet::binary_coefficient( const StringSet& the_second_set)
{
double coefficient;
StringSet intersection = the_second_set + set;
coefficient = intersection.no_of_strings() / sqrt((double) no_of_strings()) * sqrt((double)the_second_set.no_of_strings());
return coefficient;
}
However when I try and calculate the coefficient using the following main function:
// Exercise13.cpp : main project file.
#include "stdafx.h"
#include <boost/regex.hpp>
#include "StringSet.h"
using namespace System;
using namespace System::Runtime::InteropServices;
using namespace boost;
//This function takes as input a string, which
//is then broken down into a series of words
//where the punctuaction is ignored.
StringSet break_string( const string the_string)
{
regex re;
cmatch matches;
StringSet words;
string search_pattern = "\\b(\\w)+\\b";
try
{
// Assign the regular expression for parsing.
re = search_pattern;
}
catch( regex_error& e)
{
cout << search_pattern << " is not a valid regular expression: \""
<< e.what() << "\"" << endl;
exit(1);
}
sregex_token_iterator p(the_string.begin(), the_string.end(), re, 0);
sregex_token_iterator end;
for( ; p != end; ++p)
{
string new_string(p->first, p->second);
String^ copy_han = gcnew String(new_string.c_str());
String^ copy_han2 = copy_han->ToLower();
char* str2 = (char*)(void*)Marshal::StringToHGlobalAnsi(copy_han2);
string new_string2(str2);
words.add_string(new_string2);
}
return words;
}
int main(array<System::String ^> ^args)
{
StringSet words = break_string("Here is a string, with some; words");
StringSet words2 = break_string("There is another string,");
cout << words.binary_coefficient(words2);
return 0;
}
I get an index which is 1.5116 rather than a value from 0 to 1.
Does anybody have a clue why this is the case?
Any help would be appreciated.
