/**
* Copyright (C) 2009 - present by OpenGamma Inc. and the OpenGamma group of companies
*
* Please see distribution for license.
*/
package com.opengamma.analytics.math.interpolation;
import java.util.List;
import org.apache.commons.lang.Validate;
import com.opengamma.analytics.math.function.Function1D;
import com.opengamma.analytics.math.interpolation.data.InterpolatorNDDataBundle;
import com.opengamma.analytics.math.interpolation.data.KrigingInterpolatorDataBundle;
import com.opengamma.util.tuple.Pair;
/**
*
*/
public class KrigingInterpolatorND extends InterpolatorND {
private final double _beta;
public KrigingInterpolatorND(final double beta) {
Validate.isTrue(beta >= 1 && beta < 2, "Beta was not in acceptable range (1 <= beta < 2");
_beta = beta;
}
@Override
public Double interpolate(final InterpolatorNDDataBundle data, final double[] x) {
validateInput(data, x);
Validate.isTrue(data instanceof KrigingInterpolatorDataBundle, "KriginInterpolatorND needs a KriginInterpolatorDataBundle");
KrigingInterpolatorDataBundle krigingData = (KrigingInterpolatorDataBundle) data;
final List<Pair<double[], Double>> rawData = krigingData.getData();
final Function1D<Double, Double> variogram = krigingData.getVariogram();
final double[] w = krigingData.getWeights();
final int n = rawData.size();
double sum = 0.0;
double r;
for (int i = 0; i < n; i++) {
r = DistanceCalculator.getDistance(x, rawData.get(i).getFirst());
sum += variogram.evaluate(r) * w[i];
}
sum += w[n];
return sum;
}
@Override
public KrigingInterpolatorDataBundle getDataBundle(final double[] x, final double[] y, final double[] z, final double[] values) {
return new KrigingInterpolatorDataBundle(transformData(x, y, z, values), _beta);
}
@Override
public KrigingInterpolatorDataBundle getDataBundle(final List<Pair<double[], Double>> data) {
return new KrigingInterpolatorDataBundle(data, _beta);
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
long temp;
temp = Double.doubleToLongBits(_beta);
result = prime * result + (int) (temp ^ (temp >>> 32));
return result;
}
@Override
public boolean equals(final Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
final KrigingInterpolatorND other = (KrigingInterpolatorND) obj;
return Double.doubleToLongBits(_beta) == Double.doubleToLongBits(other._beta);
}
}