/// <summary>
/// get Mean Absolute Error
/// return -1 means no MAE
/// </summary>
/// <returns>return -1 means no MAE</returns>
private double _GetMAE(List <AnimeStat> predictions, List <AnimeStat> myScoresList20)
{
double absoluteError = 0;
int n = 0;
foreach (var item in predictions)
{
AnimeStat predict = myScoresList20.Find(x => x.AnimeId == item.AnimeId);
absoluteError = absoluteError + Math.Abs(predict.Score - item.Score);
n++;
}
if (n == 0)
{
return(-1);
}
else
{
return(absoluteError / n);
}
}
/// <summary>
/// get Root Mean Square Error(deviation)
/// return -1 means no MAE
/// </summary>
/// <returns></returns>
private double _GetRMSE(List <AnimeStat> predictions, List <AnimeStat> myScoresList20)
{
double squareError = 0;
int n = 0;
foreach (var item in predictions)
{
AnimeStat predict = myScoresList20.Find(x => x.AnimeId == item.AnimeId);
squareError = squareError + Math.Pow((predict.Score - item.Score), 2);
n++;
}
double rmse = Math.Sqrt(squareError / (n - 1));
if (n <= 1 || double.IsNaN(rmse))
{
return(-1);
}
else
{
return(rmse);
}
}