/// <summary>
/// Interpolating a line in 2D
/// </summary>
/// <param name="startX">X coordinate of starting point</param>
/// <param name="startY">Y coordinate of starting point</param>
/// <param name="endX">X coordinate of ending point</param>
/// <param name="endY">X coordinate of ending point</param>
/// <param name="count">Count of points</param>
/// <returns></returns>
public static double[,] InterpolateLine2D(double startX, double startY, double endX, double endY, int count)
{
double[,] ret = new double[count, 2];
try
{
double[] xCoordinates = DistributionHelper.Subdivide(new double[2] {
startX, endX
}, count + 1);
double[] yCoordinates = DistributionHelper.Subdivide(new double[2] {
startY, endY
}, count + 1);
for (int i = 0; i < count; i++)
{
ret[i, 0] = xCoordinates[i];
ret[i, 1] = yCoordinates[i];
}
}
catch
{
}
return(ret);
}
/// <summary>
/// Reproduces an initial distribution of a variable according to the empirical histogram
/// </summary>
/// <param name="mesh">Mesh</param>
/// <param name="array">Value distribution</param>
/// <param name="countBins">Count of bins</param>
/// <returns></returns>
public static void ReproduceDistribution(this Mesh mesh, double[] array, int countBins = 10)
{
try
{
//Subdividing into bins
double[] bins = DistributionHelper.Subdivide(array, countBins);
//Getting value counts for each bin
int[] counts = DistributionHelper.Counts(array, bins);
List <double> frequencies = new List <double>();
for (int i = 0; i < counts.Length; i++)
{
frequencies.Add((double)counts[i] / (double)array.Length);
counts[i] = Convert.ToInt32(Math.Round(frequencies[i] * mesh.Vertices.Count()));
}
//Creating a list of vertex indices
List <int> indices = new List <int>();
for (int i = 0; i < mesh.Vertices.Count(); i++)
{
indices.Add(i);
}
//Shuffling the list for random access
indices.Shuffle();
//Assigning a random value in the range of the selected bin to each vertex
for (int i = 0; i < bins.Length - 1; i++)
{
List <int> verticesIndices = indices.Take(counts[i]).ToList();
indices.RemoveRange(0, counts[i]);
for (int j = 0; j < counts[i]; j++)
{
double min = bins[i];
double max = bins[i + 1];
double r1 = Convert.ToDouble(rnd.NextDouble() * (max - min) + min);
mesh.Vertices[verticesIndices[j]].Value[0] = r1;
}
}
double mean = array.Average();
//Assigning not-assigned values
foreach (int index in indices)
{
mesh.Vertices[index].Value[0] = mean;
}
}
catch
{
}
}
/// <summary>
/// Calculates the DykstraParsonCoefficient
/// </summary>
/// <param name="distribution"></param>
/// <returns></returns>
public static double?CalculateDykstraParsonCoefficient(double[] distribution)
{
try
{
if (distribution == null || distribution.Count() == 0)
{
double perc84 = (double)DistributionHelper.CalculateNthPercentile(distribution, 84);
double med = (double)DistributionHelper.CalculateMedian(distribution);
return((med - perc84) / med);
}
else
{
return(0);
}
}
catch
{
return(0);
}
}
/// <summary>
/// Calculates the coefficient of variation
/// </summary>
/// <param name="distribution"></param>
/// <returns></returns>
public static double?CalculateCoefficientOfVariation(double[] distribution)
{
try
{
if (distribution == null || distribution.Count() == 0)
{
double sta = (double)DistributionHelper.CalculateStandardDeviation(distribution);
double av = distribution.Average();
return(sta / av);
}
else
{
return(0);
}
}
catch
{
return(0);
}
}
public static List <XY> ExperimentalVariogram(List <LocationValue <double> > dataSet, int steps = 10)
{
//Initialising the list of variogram values
List <XY> variogramValues = new List <XY>();
for (int a = 0; a < steps; a++)
{
variogramValues.Add(new XY());
}
if (dataSet != null)
{
if (dataSet.Count < 1)
{
return(variogramValues);
}
}
else
{
return(variogramValues);
}
List <XY> valuesDistance = new List <XY>();
dataSet = dataSet.OrderBy(x => x.X).OrderBy(x => x.Y).OrderBy(x => x.Z).ToList();
//Subdividing into bins
//Converting coordinates of points to distances
foreach (var pt in dataSet)
{
var begin = dataSet.First();
var value = pt.Value;
XY valDist = new XY();
if (pt.Geographic)
{
//Calculating the distance between the first point and every other point
var distValue = EuclideanDistance(0, 0, 0, true, begin.Latitude, begin.Longitude, pt.Latitude, pt.Longitude);
valDist.Y = distValue;
}
else
{
//Calculating the distance between the first point and every other point
var distValue = EuclideanDistance(pt.X - begin.X, pt.Y - begin.Y, pt.Z - begin.Z);
valDist.Y = distValue;
}
valDist.X = pt.Value;
valuesDistance.Add(valDist);
}
double[] bins = DistributionHelper.Subdivide(valuesDistance.Select(x => x.Y).ToArray(), steps);
//Getting all values of a bin
for (int i = 0; i < bins.Count(); i++)
{
variogramValues[i].X = bins[i];
List <XY> valuesInRange = new List <XY>((from valueDistance in valuesDistance
where valueDistance.Y <= bins[i]
select valueDistance).ToList());
for (int j = 0; j < valuesInRange.Count(); j++)
{
if (j == 0)
{
continue;
}
int n = valuesInRange.Count();
double val = 0;
for (int z = 0; z <= n - j; z++)
{
val += Math.Pow(valuesInRange[n - (z + 1)].X - valuesInRange[j].X, 2);
}
variogramValues[i].Y = val / n;
}
}
return(variogramValues);
}
