static public string findMostLikelyGenre(Data.BookData bookTested, List <Data.BookData> books, int n)
{
Data.BookData[] ListOfClosestBooks = getNClosestPoints(bookTested, books, n);
Dictionary <string, double> oddsByGenre = new Dictionary <string, double>();
for (int i = 0; i < ListOfClosestBooks.Length; i++)
{
if (!oddsByGenre.ContainsKey(ListOfClosestBooks[i].Genre))
{
oddsByGenre.Add(ListOfClosestBooks[i].Genre, 0);
}
oddsByGenre[ListOfClosestBooks[i].Genre]++;
}
string bestGuess = "";
double highest = -1;
foreach (KeyValuePair <string, double> element in oddsByGenre)
{
if (element.Value > highest)
{
highest = element.Value;
bestGuess = element.Key;
}
}
return(bestGuess);
}
static public string getClassOfBookBayes(Data.BookData bookTested, Dictionary <string, WordOddsBayes> wordOddsPerGenre)
{
double[] OddsPerOutcome = new double[wordOddsPerGenre.Count];
//set everthing to 1 as we need to multiply times this to increment it
for (int i = 0; i < OddsPerOutcome.Length; i++)
{
OddsPerOutcome[i] = 1;
}
//we use the foreach because it's eaaser to itterate through a dictinary with that. But we need to get the index per word
int counter = 0;
string bestGuess = "";
foreach (KeyValuePair <string, WordOddsBayes> Genre in wordOddsPerGenre)
{
//foreach (KeyValuePair<string, int> word in bookTested.WordCounts)
//{
// OddsPerOutcome[counter] = OddsPerOutcome[counter] * Genre.Value.OneSampleZTest(word.Value, word.Key);
//}
for (int i = 0; i < arrayOfBestWords.Length; i++)
{
string word = arrayOfBestWords[i];
double occuranceInBook = 0;
if (bookTested.WordCounts.ContainsKey(word))
{
occuranceInBook = bookTested.WordCounts[word];
}
OddsPerOutcome[counter] = OddsPerOutcome[counter] * Genre.Value.OneSampleZTest(occuranceInBook, word);
}
bool shouldStateCurrentGenreAsBest = true;
if (counter == 0)
{
bestGuess = Genre.Key;
}
for (int altCount = 0; altCount < counter; altCount++)
{
if (OddsPerOutcome[altCount] > OddsPerOutcome[counter])
{
shouldStateCurrentGenreAsBest = false;
}
if (shouldStateCurrentGenreAsBest)
{
bestGuess = Genre.Key;
}
}
counter++;
}
return(bestGuess);
}
//n is the number of closest points you want, always set it to something odd
static public Data.BookData[] getNClosestPoints(Data.BookData bookTested, List <Data.BookData> books, int n)
{
double[] distances = new double[n];
Data.BookData[] nClosestBooks = new Data.BookData[n];
//if there are more than one hundred million of the same words in a book we can establish that something is wrong in the world
for (int i = 0; i < distances.Length; i++)
{
distances[i] = 100000000;
}
foreach (Data.BookData bookDataPoint in books)
{
//if the book data point has the same memory address we know this will be the same and we don't want to test it
if (bookDataPoint != bookTested)
{
double distanceBetweenBooks = getEucDistance(bookTested, bookDataPoint);
//this is for manhatten distance
//double distanceBetweenBooks = getManhattenDistance(bookTested, bookDataPoint);
//a simple loop to find the highest distance so far. This is the one to test against and replace
int indexOfHighestDistance = 0;
for (int i = 0; i < distances.Length; i++)
{
if (distances[indexOfHighestDistance] < distances[i])
{
indexOfHighestDistance = i;
}
}
if (distances[indexOfHighestDistance] > distanceBetweenBooks)
{
//if the furthest out point so far is further out than the newest book point we can assume
distances[indexOfHighestDistance] = distanceBetweenBooks;
nClosestBooks[indexOfHighestDistance] = bookDataPoint;
}
}
}
return(nClosestBooks);
}
