private static float[][] Map(float[][] records, float error, int maxIter, int resultDimensions)
{
var n = records.Length;
var dDistances = JaggedArray.Init <float>(n, n);
var yDistances = JaggedArray.Init <float>(n, n);
var dedy = JaggedArray.Init <float>(n, resultDimensions);
var d2edy2 = JaggedArray.Init <float>(n, resultDimensions);
var deltas = JaggedArray.Init <float>(n, resultDimensions);
var ys = CalculateInitialConfiguration(n: records.Length, d: resultDimensions);
var alpha = 0.3f;
var iteration = 0;
var e = 0.0f;
do
{
CalculateDistances(dDistances, yDistances, records, ys);
CalculatePartialDerivatives(dedy, d2edy2, dDistances, yDistances, ys);
CalculateDeltas(deltas, dedy, d2edy2);
CalculateNewConfiguration(ys, deltas, alpha);
e = CalculateError(dDistances, yDistances);
} while(e > error || iteration++ < maxIter);
return(ys);
}
public static float[][] RandomPartitioning(float[][] records, int k)
{
Debug.Assert(k > 0);
var rng = new Random((int)DateTime.Now.Ticks);
var centroids = JaggedArray.Init <float>(k, records[0].Length);
var labels = new int[records.Length];
// Assign each record to random cluster
for (var i = 0; i < records.Length; ++i)
{
labels[i] = rng.Next(k);
}
Compute(centroids, records, labels);
return(centroids);
}
