/**
* Subspace relevance test.
*
* @param subspace Subspace to test
* @param neigh Neighbor list
* @param kernel Kernel density estimator
* @return relevance test result
*/
protected boolean relevantSubspace(
long[] subspace, DoubleDBIDList neigh, KernelDensityEstimator kernel) {
Relation<V> relation = kernel.relation;
final double crit = K_S_CRITICAL001 / Math.sqrt(neigh.size());
for (int dim = BitsUtil.nextSetBit(subspace, 0);
dim > 0;
dim = BitsUtil.nextSetBit(subspace, dim + 1)) {
// TODO: can we save this copy somehow?
double[] data = new double[neigh.size()];
{
int count = 0;
for (DBIDIter neighbor = neigh.iter(); neighbor.valid(); neighbor.advance()) {
V vector = relation.get(neighbor);
data[count] = vector.doubleValue(dim);
count++;
}
assert (count == neigh.size());
}
Arrays.sort(data);
final double norm = data[data.length - 1] - data[0];
final double min = data[0];
// Kolmogorow-Smirnow-Test against uniform distribution:
for (int j = 1; j < data.length - 2; j++) {
double delta = (j / (data.length - 1.)) - ((data[j] - min) / norm);
if (Math.abs(delta) > crit) {
return false;
}
}
}
return true;
}
@Override
protected double minDistObject(SpatialComparable mbr, NumberVector v) {
if (mbr.getDimensionality() != v.getDimensionality()) {
throw new IllegalArgumentException(
"Different dimensionality of objects\n "
+ "first argument: "
+ mbr.toString()
+ "\n "
+ "second argument: "
+ v.toString());
}
double agg = 0.;
for (int d = BitsUtil.nextSetBit(dimensions, 0);
d >= 0;
d = BitsUtil.nextSetBit(dimensions, d + 1)) {
final double value = v.doubleValue(d);
final double omin = mbr.getMin(d);
final double diff1 = omin - value;
if (diff1 > 0.) {
if (diff1 > agg) {
agg = diff1;
}
} else {
final double omax = mbr.getMax(d);
final double diff2 = value - omax;
if (diff2 > agg) {
agg = diff2;
}
}
}
return agg;
}
@Override
public double minDist(SpatialComparable mbr1, SpatialComparable mbr2) {
if (mbr1.getDimensionality() != mbr2.getDimensionality()) {
throw new IllegalArgumentException(
"Different dimensionality of objects\n "
+ "first argument: "
+ mbr1.toString()
+ "\n "
+ "second argument: "
+ mbr2.toString());
}
double agg = 0.;
for (int d = BitsUtil.nextSetBit(dimensions, 0);
d >= 0;
d = BitsUtil.nextSetBit(dimensions, d + 1)) {
final double max1 = mbr1.getMax(d);
final double min2 = mbr2.getMin(d);
if (max1 < min2) {
double v = min2 - max1;
if (v > agg) {
agg = v;
}
} else {
final double min1 = mbr1.getMin(d);
final double max2 = mbr2.getMax(d);
double v = min1 - max2;
if (v > agg) {
agg = v;
}
}
}
return agg;
}
@Override
public double norm(NumberVector obj) {
double agg = 0.;
for (int d = BitsUtil.nextSetBit(dimensions, 0);
d >= 0;
d = BitsUtil.nextSetBit(dimensions, d + 1)) {
double v = Math.abs(obj.doubleValue(d));
if (v > agg) {
agg = v;
}
}
return agg;
}
@Override
public double distance(NumberVector v1, NumberVector v2) {
if (v1.getDimensionality() != v2.getDimensionality()) {
throw new IllegalArgumentException(
"Different dimensionality of FeatureVectors\n "
+ "first argument: "
+ v1
+ "\n "
+ "second argument: "
+ v2);
}
double agg = 0.;
for (int d = BitsUtil.nextSetBit(dimensions, 0);
d >= 0;
d = BitsUtil.nextSetBit(dimensions, d + 1)) {
double v = Math.abs(v1.doubleValue(d) - v2.doubleValue(d));
if (v > agg) {
agg = v;
}
}
return agg;
}
