来自ml.net的正弦预测实际上不起作用

我目前正在尝试使用ml.net,但在第一个项目中我就陷入了困境。我试图预测正弦值。

1. 用正弦函数(y=sin(x))生成x和y值列表
2. 使用ml.net的列表学习
3. 对下一个x值进行y预测
4. 将这些预测附加到列表中

结果:对于以下任何数字,我总是得到一个结果。 正弦是一个可变函数。

这是当前代码:

class Program
{
    private const string FILEPATH = @"sinus.txt";
    private const float XSTART = 0f;
    private const float XEND = 20f;
    private const float XSTEP = 0.1f;
    private const float XEND_FORECAST = 30f;

    static void Main(string[] args)
    {
        GenerateSinusList();

        var pipeline = new LearningPipeline();
        pipeline.Add(new TextLoader(FILEPATH).CreateFrom<Sinus>(separator: ';'));
        pipeline.Add(new ColumnConcatenator("Features", "X"));
        pipeline.Add(new FastTreeRegressor());

        var model = pipeline.Train<Sinus, SinusForecast>();
        PredictUpcomingValues(model);

        Console.WriteLine("done");
        Console.ReadLine();
    }

    static void PredictUpcomingValues(PredictionModel<Sinus, SinusForecast> model)
    {
        using (var sw = System.IO.File.AppendText(FILEPATH))
        {
            sw.WriteLine();
            for (double i = XEND + XSTEP; i < XEND_FORECAST; i += XSTEP)
            {
                var prediction = model.Predict(new Sinus() { X = (float)i });
                var t = string.Format("{0};{1}", i, prediction.ResultY);
                sw.WriteLine(t.Replace(',', '.')); //Quick localization fixSine
            }
            sw.Close();
        }
    }

    static void GenerateSinusList()
    {
        var sinus = GenerateSine(XSTART, XEND, XSTEP);
        var text = string.Join(System.Environment.NewLine, sinus.Select(x => string.Format("{0:};{1}", x.Key, x.Value)));
        System.IO.File.WriteAllText(FILEPATH, text.Replace(',', '.'));

    }

    static Dictionary<float, float> GenerateSine(float from, float to, float step)
    {
        Dictionary<float, float> result = new Dictionary<float, float>((int)((to - from) / step) + 1);

        for (double i = from; i < to; i += step)
        {
            result[(float)i] = (float)Math.Sin(i);
        }
        return result;
    }

    public class Sinus
    {
        [Column("0")]
        public float X;

        [Column("1", name: "Label")]
        public float Y;
    }

    public class SinusForecast
    {
        [ColumnName("Score")]
        public float ResultY;
    }

}

结果是:每个值>20返回0.5429355。列表如下:

• …
• 19.4;0.523066
• 19.5;0.6055401
• 19.6;0.6819639
• 19.7;0.7515736
• 19.8;0.8136739
• 19.9;0.8676443
• 20.1;0.5429355<<首次预测
• 20.2;0.5429355
• 20.3;0.5429355
• 20.4;0.5429355
• 20.5;0.5429355
• 20.6;0.5429355
• …

编辑:我正在使用ml 0.4.0