internal static XGBArray ConvertToXGBArray <T>(XGVector <T>[] vectorsTrain)
{
var arr = new XGBArray();
arr.Labels = vectorsTrain.Select(v => v.Label).ToArray();
arr.Vectors = vectorsTrain.Select(v => v.Features).ToArray();
return(arr);
}
/// <summary>
/// Combines the lables and vectors from array 1 and array 2
/// </summary>
/// <param name="arr1">First array of vectors and labels</param>
/// <param name="arr2">Second array of vectors and labels</param>
/// <returns></returns>
internal static XGBArray UnionOfXGBArray(XGBArray arr1, XGBArray arr2)
{
var arrUnion = new XGBArray
{
Labels = Enumerable.Concat(arr1.Labels, arr2.Labels).ToArray(),
Vectors = Enumerable.Concat(arr1.Vectors, arr2.Vectors).ToArray()
};
return(arrUnion);
}
/// <summary>
/// Combines all the lables and vectors into a single struct
/// </summary>
/// <param name="arrs"></param>
/// <returns></returns>
internal static XGBArray UnionOfXGBArrays(params XGBArray[] arrs)
{
var arrUnion = new XGBArray
{
Labels = new float[] { },
Vectors = new float[][] { }
};
foreach (var arr in arrs)
{
arrUnion.Vectors = arrUnion.Vectors.Concat(arr.Vectors).ToArray();
arrUnion.Labels = arrUnion.Labels.Concat(arr.Labels).ToArray();
}
return(arrUnion);
}
/// <summary>
/// Generates random number of points whose X,Y fall within the specified min,max ranges
/// When to use this function? Use this for generating labelled training vectors
/// </summary>
/// <param name="count">No of points to generate</param>
/// <param name="minX">Lower limit of the X value of points</param>
/// <param name="maxX">Upper limit of the X value of points</param>
/// <param name="minY">Lower limit of the Y value of points</param>
/// <param name="maxY">Upper limit of the Y value of points</param>
/// <param name="label">The numeric class label for these points</param>
/// <returns></returns>
internal static XGBArray GenerateRandom2dPoints(int count, double minX, double maxX, double minY, double maxY, double label)
{
var lstPoints = new List <Tuple <float, float> >();//Item1=X, Item2=Y
var lstLabels = new List <float>();
for (int i = 0; i < count; i++)
{
float x = (float)(_rnd.NextDouble() * (maxX - minX) + minX);
float y = (float)(_rnd.NextDouble() * (maxY - minY) + minY);
var tPoint = new Tuple <float, float>(x, y);
lstPoints.Add(tPoint);
}
var rs = new XGBArray
{
Labels = Enumerable.Repeat <float>((float)label, count).ToArray(),
Vectors = lstPoints.Select(t => new float[] { t.Item1, t.Item2 }).ToArray()
};
return(rs);
}
