public static double[] ComputeRegressionNumerics(LasFile file, LasPoint point, int count, int radiusSector)
{
var neighbours = file.LasPointDataRecords.GetNeighbours(point, count, radiusSector);
double[][] xy = new double[neighbours.Count][];
double[] z = new double[neighbours.Count];
for (int i = 0; i < neighbours.Count; i++)
{
xy[i] = new double[] { neighbours[i].X, neighbours[i].Y };
z[i] = neighbours[i].Z;
}
double[] p = MultipleRegression.QR(xy, z);
return(p);
}
public static Tuple <double[][], int[]> MakeInputOutputs(List <LasPoint> points, LasFile file)
{
int count = points.Count;
int[] outputs = new int[count];
double[][] inputs = new double[count][];
for (int i = 0; i < count; i++)
{
LasPoint point = points[i];
Console.WriteLine("Preparing Teaching Dataset " + i + "/" + count);
var inout = GetInputOutputFromClassificationType(point, file);
inputs[i] = inout.Item1;
outputs[i] = inout.Item2;
}
return(new Tuple <double[][], int[]>(inputs, outputs));
}
public static Tuple <double[], int> GetInputOutputFromClassificationType(LasPoint point, LasFile file)
{
var abc = LinearRegression.ComputeRegressionPoint(file, point, regressionCount, regressionRange);
double distanceFromPlane = Utills.DistanceFromPlane(point, abc);
LasPoint3Short pointShort = (LasPoint3Short)point;
double green = pointShort.Green - (pointShort.Red + pointShort.Blue) / 2;
var input = new double[] { green, file.LasHeader.ScaleZ(point.Z), point.Intensity, abc.X, abc.Y, abc.Z, distanceFromPlane };
int output;
switch (point.Classification)
{
case LasPoint.ClassificationType.Ground:
output = 0;
break;
case LasPoint.ClassificationType.HighVegetation:
output = 1;
break;
case LasPoint.ClassificationType.Building:
output = 2;
break;
case LasPoint.ClassificationType.MediumVegetation:
output = 3;
break;
case LasPoint.ClassificationType.LowVegetation:
output = 4;
break;
case LasPoint.ClassificationType.Water:
output = 5;
break;
default:
input = new double[] { -1, -1, -1, -1, -1, -1, -1 };
output = 6;
break;
}
return(Tuple.Create(input, output));
}
public static Tuple <double[], int> GetInputOutputFromClassificationType(LasPoint point, LasFile file)
{
LasPoint3Short pointShort = (LasPoint3Short)point;
double green = pointShort.Green - (pointShort.Red + pointShort.Blue) / 2;
var input = new double[] { file.LasHeader.ScaleZ(point.Z), point.Intensity, green };
int output;
switch (point.Classification)
{
case LasPoint.ClassificationType.Ground:
output = 0;
break;
case LasPoint.ClassificationType.HighVegetation:
output = 1;
break;
case LasPoint.ClassificationType.Building:
output = 2;
break;
case LasPoint.ClassificationType.MediumVegetation:
output = 3;
break;
case LasPoint.ClassificationType.LowVegetation:
output = 4;
break;
case LasPoint.ClassificationType.Water:
output = 5;
break;
default:
input = new double[] { -1, -1, -1 };
output = 6;
break;
}
return(Tuple.Create(input, output));
}
public static Vector3 ComputeRegressionPoint(LasFile file, LasPoint point, int count, int radiusSector)
{
var neighbours = file.LasPointDataRecords.GetNeighbours(point, count, radiusSector);
double[,] matrix = new double[3, 3];
double[,] vector = new double[1, 3];
foreach (var item in neighbours)
{
matrix[0, 0] += item.X * item.X;
matrix[0, 1] += item.X * item.Y;
matrix[0, 2] += item.X;
matrix[1, 0] += item.X * item.Y;
matrix[1, 1] += item.Y * item.Y;
matrix[1, 2] += item.Y;
matrix[2, 0] += item.X;
matrix[2, 1] += item.Y;
vector[0, 0] += item.X * item.Z;
vector[0, 1] += item.Y * item.Z;
vector[0, 2] += item.Z;
}
matrix[2, 2] = neighbours.Count;
Matrix <double> a = DenseMatrix.OfArray(matrix);
Matrix <double> b = DenseMatrix.OfArray(vector);
a = a.Inverse();
Matrix <double> x = b.Multiply(a);
var tempArray = x.ToArray();
Vector3 abc = new Vector3(Convert.ToSingle(tempArray[0, 0]), Convert.ToSingle(tempArray[0, 1]), Convert.ToSingle(tempArray[0, 2]));
return(abc);
}
public static double DistanceFromPlane(LasPoint point, Vector3 abc)
{
return(((abc.X * point.X) + (abc.Y * point.Y) + (abc.Z * point.Z)) / ((abc.X * abc.X) + (abc.Y * abc.Y) + (abc.Z * abc.Z)));
}
