/**
* @param xData
* @param yData
* @param contentData
* @param initialDistance
* @param stepSize
* @param maxDistance
* @return
* @throws Exception
*/
public static Matrix variogram2D(
ArrayList<Double> xData,
ArrayList<Double> yData,
ArrayList<Double> contentData,
double initialDistance,
double stepSize,
double maxDistance)
throws Exception {
Matrix result;
if (xData.size() != yData.size()) {
throw new Exception("Values of X and Y must have same size.");
} else {
double aux = ((maxDistance - initialDistance) / stepSize);
int linesNumber = (int) aux;
if (linesNumber <= 0) {
throw new Exception("Invalid Values");
} else {
result = new Matrix(3, linesNumber);
for (int currentLine = 0; currentLine < linesNumber; currentLine++) {
double value = 0.;
int pairsNumber = 0;
for (int i = 0; i < xData.size(); i++) {
for (int j = i + 1; j < xData.size(); j++) {
double distanceX = xData.get(i).doubleValue() - xData.get(j).doubleValue();
double distanceY = yData.get(i).doubleValue() - yData.get(j).doubleValue();
double distance = Math.sqrt(Math.pow(distanceX, 2) + Math.pow(distanceY, 2));
if (distance >= initialDistance && distance <= initialDistance + stepSize) {
value +=
Math.pow(
contentData.get(i).doubleValue() - contentData.get(j).doubleValue(), 2);
pairsNumber++;
}
}
}
result.set(0, currentLine, initialDistance + stepSize);
initialDistance += stepSize;
value /= 2 * pairsNumber;
result.set(1, currentLine, value);
result.set(2, currentLine, pairsNumber);
}
}
}
return result;
}
/**
* @param matrix
* @param initialDistance
* @param stepSize
* @param maxDistance
* @param columnX
* @param columnY
* @param columnContent
* @return
* @throws Exception
*/
public static Matrix variogram2D(
Matrix matrix,
double initialDistance,
double stepSize,
double maxDistance,
int columnX,
int columnY,
int columnContent)
throws Exception {
double aux = ((maxDistance - initialDistance) / stepSize);
int linesNumber = (int) aux;
Matrix result = new Matrix(3, linesNumber);
if (matrix.getColumnsCount() != matrix.getLinesCount()) {
throw new Exception("Must be a square matrix");
} else {
for (int currentLine = 0; currentLine < linesNumber; currentLine++) {
double value = 0.;
int pairsNumber = 0;
for (int i = 0; i < matrix.getLinesCount(); i++) {
for (int j = i + 1; j < matrix.getColumnsCount(); j++) {
double distanceX =
matrix.get(columnX, i).doubleValue() - matrix.get(columnX, j).doubleValue();
double distanceY =
matrix.get(columnY, i).doubleValue() - matrix.get(columnY, j).doubleValue();
double distance = Math.sqrt(Math.pow(distanceX, 2) + Math.pow(distanceY, 2));
if (distance >= initialDistance && distance <= initialDistance + stepSize) {
value +=
Math.pow(
matrix.get(columnContent, i).doubleValue()
- matrix.get(columnContent, j).doubleValue(),
2);
pairsNumber++;
}
}
}
result.set(0, currentLine, initialDistance + stepSize);
initialDistance += stepSize;
value /= 2 * pairsNumber;
result.set(1, currentLine, value);
result.set(2, currentLine, pairsNumber);
}
}
return result;
}