public static double ManhattanDistance(Lection lection1, Lection lection2)
{
double distance = 0;
distance += Math.Abs(lection1.Rating - lection2.Rating) * RatingWeight;
distance += Math.Abs(lection1.Pages - lection2.Pages) * PagesWeight;
distance += Math.Abs(lection1.ThemesCount - lection2.ThemesCount) * ThemesCountWeight;
distance += Math.Abs(lection1.Year - lection2.Year) * YearWeight;
return(distance);
}
public static double EuqlidDistance(Lection lection1, Lection lection2)
{
double distance = 0;
distance += Math.Sqrt(Math.Abs(Math.Pow(lection1.Rating, 2) - Math.Pow(lection2.Rating, 2))) * RatingWeight;
distance += Math.Sqrt(Math.Abs(Math.Pow(lection1.Pages, 2) - Math.Pow(lection2.Pages, 2))) * PagesWeight;
distance += Math.Sqrt(Math.Abs(Math.Pow(lection1.ThemesCount, 2) - Math.Pow(lection2.ThemesCount, 2))) * ThemesCountWeight;
distance += Math.Sqrt(Math.Abs(Math.Pow(DateTime.Now.Year - lection1.Year, 2) - Math.Pow(DateTime.Now.Year - lection2.Year, 2))) * YearWeight;
return(distance);
}
public static int EqualValues(Lection lection1, Lection lection2)
{
int result = 0;
if (lection1.Pages == lection2.Pages)
{
result++;
}
if (lection1.ThemesCount == lection2.ThemesCount)
{
result++;
}
if (lection1.Subject == lection2.Subject)
{
result++;
}
if (lection1.Author == lection2.Author)
{
result++;
}
//if (lection1.Country == lection2.Country)
//{
// result++;
//}
if (lection1.Rating == lection2.Rating)
{
result++;
}
if (lection1.University == lection2.University)
{
;
}
{
result++;
}
if (lection1.Language == lection2.Language)
{
;
}
{
result++;
}
if (lection1.Year == lection2.Year)
{
result++;
}
return(result);
}
public static double CorrelationDistance(Lection lection1, Lection lection2)
{
var values1 = new double[] { DateTime.Now.Year - lection1.Year, lection1.Rating, lection1.ThemesCount, lection1.Pages };
var values2 = new double[] { DateTime.Now.Year - lection2.Year, lection2.Rating, lection2.ThemesCount, lection2.Pages };
if (values1.Length != values2.Length)
{
throw new ArgumentException("values must be the same length");
}
var avg1 = values1.Average();
var avg2 = values2.Average();
var sum1 = values1.Zip(values2, (x1, y1) => (x1 - avg1) * (y1 - avg2)).Sum();
var sumSqr1 = values1.Sum(x => Math.Pow((x - avg1), 2.0));
var sumSqr2 = values2.Sum(y => Math.Pow((y - avg2), 2.0));
var result = sum1 / Math.Sqrt(sumSqr1 * sumSqr2);
return(result);
}