/**
* Computes the volume of the overlapping box between two SpatialComparables.
*
* @param box1 the first SpatialComparable
* @param box2 the second SpatialComparable
* @return the overlap volume.
*/
public static double overlap(SpatialComparable box1, SpatialComparable box2) {
final int dim = assertSameDimensionality(box1, box2);
// the maximal and minimal value of the overlap box.
double omax, omin;
// the overlap volume
double overlap = 1.;
for (int i = 0; i < dim; i++) {
// The maximal value of that overlap box in the current
// dimension is the minimum of the max values.
omax = Math.min(box1.getMax(i), box2.getMax(i));
// The minimal value is the maximum of the min values.
omin = Math.max(box1.getMin(i), box2.getMin(i));
// if omax <= omin in any dimension, the overlap box has a volume of zero
if (omax <= omin) {
return 0.;
}
overlap *= omax - omin;
}
return overlap;
}
/**
* Computes the volume of the overlapping box between two SpatialComparables and return the
* relation between the volume of the overlapping box and the volume of both SpatialComparable.
*
* @param box1 the first SpatialComparable
* @param box2 the second SpatialComparable
* @return the overlap volume in relation to the singular volumes.
*/
public static double relativeOverlap(SpatialComparable box1, SpatialComparable box2) {
final int dim = assertSameDimensionality(box1, box2);
// the overlap volume
double overlap = 1.;
double vol1 = 1.;
double vol2 = 1.;
for (int i = 0; i < dim; i++) {
final double box1min = box1.getMin(i);
final double box1max = box1.getMax(i);
final double box2min = box2.getMin(i);
final double box2max = box2.getMax(i);
final double omax = Math.min(box1max, box2max);
final double omin = Math.max(box1min, box2min);
// if omax <= omin in any dimension, the overlap box has a volume of zero
if (omax <= omin) {
return 0.;
}
overlap *= omax - omin;
vol1 *= box1max - box1min;
vol2 *= box2max - box2min;
}
return overlap / (vol1 + vol2);
}
/**
* Returns a clone of the maximum hyper point.
*
* @param box spatial object
* @return the maximum hyper point
*/
public static double[] getMax(SpatialComparable box) {
final int dim = box.getDimensionality();
double[] max = new double[dim];
for (int i = 0; i < dim; i++) {
max[i] = box.getMax(i);
}
return max;
}
/**
* Returns a clone of the minimum hyper point.
*
* @param box spatial object
* @return the minimum hyper point
*/
public static double[] getMin(SpatialComparable box) {
final int dim = box.getDimensionality();
double[] min = new double[dim];
for (int i = 0; i < dim; i++) {
min[i] = box.getMin(i);
}
return min;
}
/**
* Check that two spatial objects have the same dimensionality.
*
* @param box1 First object
* @param box2 Second object
* @return Dimensionality
* @throws IllegalArgumentException when the dimensionalities do not agree
*/
public static int assertSameDimensionality(SpatialComparable box1, SpatialComparable box2) {
final int dim = box1.getDimensionality();
if (dim != box2.getDimensionality()) {
throw new IllegalArgumentException(
"The spatial objects do not have the same dimensionality!");
}
return dim;
}
/**
* Returns the centroid of this SpatialComparable.
*
* @param obj Spatial object to process
* @return the centroid of this SpatialComparable
*/
public static double[] centroid(SpatialComparable obj) {
final int dim = obj.getDimensionality();
double[] centroid = new double[dim];
for (int d = 0; d < dim; d++) {
centroid[d] = (obj.getMax(d) + obj.getMin(d)) * .5;
}
return centroid;
}
/**
* Computes the perimeter of this SpatialComparable.
*
* @param box spatial object
* @return the perimeter of this SpatialComparable
*/
public static double perimeter(SpatialComparable box) {
final int dim = box.getDimensionality();
double perimeter = 0.;
for (int i = 0; i < dim; i++) {
perimeter += box.getMax(i) - box.getMin(i);
}
return perimeter;
}
/**
* Returns true if the two SpatialComparables intersect, false otherwise.
*
* @param box1 the first SpatialComparable
* @param box2 the first SpatialComparable
* @return true if the SpatialComparables intersect, false otherwise
*/
public static boolean intersects(SpatialComparable box1, SpatialComparable box2) {
final int dim = assertSameDimensionality(box1, box2);
for (int i = 0; i < dim; i++) {
if (box2.getMax(i) < box1.getMin(i) || box1.getMax(i) < box2.getMin(i)) {
return false;
}
}
return true;
}
/**
* Compute the volume (area) of the union of two MBRs.
*
* @param box1 First object
* @param box2 Second object
* @return Volume of union
*/
public static double volumeUnion(SpatialComparable box1, SpatialComparable box2) {
final int dim = assertSameDimensionality(box1, box2);
double volume = 1.;
for (int i = 0; i < dim; i++) {
final double min = Math.min(box1.getMin(i), box2.getMin(i));
final double max = Math.max(box1.getMax(i), box2.getMax(i));
volume *= (max - min);
}
return volume;
}
/**
* Computes the union HyperBoundingBox of two SpatialComparables.
*
* @param box1 the first SpatialComparable
* @param box2 the second SpatialComparable
* @return the union HyperBoundingBox of this HyperBoundingBox and the given HyperBoundingBox
*/
public static ModifiableHyperBoundingBox union(SpatialComparable box1, SpatialComparable box2) {
final int dim = assertSameDimensionality(box1, box2);
double[] min = new double[dim];
double[] max = new double[dim];
for (int i = 0; i < dim; i++) {
min[i] = Math.min(box1.getMin(i), box2.getMin(i));
max[i] = Math.max(box1.getMax(i), box2.getMax(i));
}
return new ModifiableHyperBoundingBox(min, max);
}
/**
* Computes the volume of this SpatialComparable.
*
* @param box Box
* @param scale Scaling factor
* @return the volume of this SpatialComparable
*/
public static double volumeScaled(SpatialComparable box, double scale) {
final int dim = box.getDimensionality();
double vol = 1.;
for (int i = 0; i < dim; i++) {
double delta = box.getMax(i) - box.getMin(i);
if (delta == 0.) {
return 0.;
}
vol *= delta * scale;
}
return vol;
}
/**
* Returns true if this SpatialComparable contains the given point, false otherwise.
*
* @param box spatial object
* @param point the point to be tested for containment
* @return true if this SpatialComparable contains the given point, false otherwise
*/
public static boolean contains(SpatialComparable box, double[] point) {
final int dim = box.getDimensionality();
if (dim != point.length) {
throw new IllegalArgumentException(
"This HyperBoundingBox and the given point need same dimensionality");
}
for (int i = 0; i < dim; i++) {
if (box.getMin(i) > point[i] || box.getMax(i) < point[i]) {
return false;
}
}
return true;
}
/**
* Compute the enlargement obtained by adding an object to an existing object.
*
* @param exist Existing rectangle
* @param addit Additional rectangle
* @return Enlargement factor
*/
public static double enlargement(SpatialComparable exist, SpatialComparable addit) {
final int dim = assertSameDimensionality(exist, addit);
double v1 = 1.;
double v2 = 1.;
for (int i = 0; i < dim; i++) {
final double emin = exist.getMin(i);
final double emax = exist.getMax(i);
final double amin = addit.getMin(i);
final double amax = addit.getMax(i);
final double min = Math.min(emin, amin);
final double max = Math.max(emax, amax);
v1 *= (max - min);
v2 *= (emax - emin);
}
return v2 - v1;
}
/**
* Test two SpatialComparables for equality.
*
* @param box1 First bounding box
* @param box2 Second bounding box
* @return true when the boxes are equal
*/
public static boolean equals(SpatialComparable box1, SpatialComparable box2) {
if (box1.getDimensionality() != box2.getDimensionality()) {
return false;
}
for (int i = 0; i < box1.getDimensionality(); i++) {
if (box1.getMin(i) != box2.getMin(i)) {
return false;
}
if (box1.getMax(i) != box2.getMax(i)) {
return false;
}
}
return true;
}
