public NonGridContourDataset() 
{
           
        super();
}

Default constructor.

 public NonGridContourDataset(String seriesName,
    Object[] xData,
    Object[] yData,
    Object[] zData) 
{
        super(seriesName, xData, yData, zData);
        buildGrid(DEFAULT_NUM_X, DEFAULT_NUM_Y, DEFAULT_POWER);
}

Constructor for NonGridContourDataset. Uses default values for grid dimensions and weighting.

Parameters:

seriesName - the series name.

xData - the x values.

yData - the y values.

zData - the z values.

 public NonGridContourDataset(String seriesName,
    Object[] xData,
    Object[] yData,
    Object[] zData,
    int numX,
    int numY,
    int power) 
{
        super(seriesName, xData, yData, zData);
        buildGrid(numX, numY, power);
}

Constructor for NonGridContourDataset.

Parameters:

seriesName - the series name.

xData - the x values.

yData - the y values.

zData - the z values.

numX - number grid cells in along the x-axis

numY - number grid cells in along the y-axis

power - exponent for inverse distance weighting

 protected  void buildGrid(int numX,
    int numY,
    int power) 
{
        int numValues = numX * numY;
        double[] xGrid = new double[numValues];
        double[] yGrid = new double [numValues];
        double[] zGrid = new double [numValues];
        // Find min, max for the x and y axes
        double xMin = 1.e20;
        for (int k = 0; k <  this.xValues.length; k++) {
            xMin = Math.min(xMin, this.xValues[k].doubleValue());
        }
        double xMax = -1.e20;
        for (int k = 0; k <  this.xValues.length; k++) {
            xMax = Math.max(xMax, this.xValues[k].doubleValue());
        }
        double yMin = 1.e20;
        for (int k = 0; k <  this.yValues.length; k++) {
            yMin = Math.min(yMin, this.yValues[k].doubleValue());
        }
        double yMax = -1.e20;
        for (int k = 0; k <  this.yValues.length; k++) {
            yMax = Math.max(yMax, this.yValues[k].doubleValue());
        }
        Range xRange = new Range(xMin, xMax);
        Range yRange = new Range(yMin, yMax);
        xRange.getLength();
        yRange.getLength();
        // Determine the cell size
        double dxGrid = xRange.getLength() / (numX - 1);
        double dyGrid = yRange.getLength() / (numY - 1);
        // Generate the grid
        double x = 0.0;
        for (int i = 0; i <  numX; i++) {
            if (i == 0) {
                x = xMin;
            }
            else {
                x += dxGrid;
            }
            double y = 0.0;
            for (int j = 0; j <  numY; j++) {
                int k = numY * i + j;
                xGrid[k] = x;
                if (j == 0) {
                    y = yMin;
                }
                else {
                    y += dyGrid;
                }
                yGrid[k] = y;
            }
        }
        // Map the nongrid data into the new regular grid
        for (int kGrid = 0; kGrid <  xGrid.length; kGrid++) {
            double dTotal = 0.0;
            zGrid[kGrid] = 0.0;
            for (int k = 0; k <  this.xValues.length; k++) {
                double xPt = this.xValues[k].doubleValue();
                double yPt = this.yValues[k].doubleValue();
                double d = distance(xPt, yPt, xGrid[kGrid], yGrid[kGrid]);
                if (power != 1) {
                    d = Math.pow(d, power);
                }
                d = Math.sqrt(d);
                if (d  > 0.0) {
                    d = 1.0 / d;
                }
                else { // if d is real small set the inverse to a large number 
                       // to avoid INF
                    d = 1.e20;
                }
                if (this.zValues[k] != null) {
                    // scale by the inverse of distance^power
                    zGrid[kGrid] += this.zValues[k].doubleValue() * d; 
                }
                dTotal += d;
            }
            zGrid[kGrid] = zGrid[kGrid] / dTotal;  //remove distance of the sum
        }
        //initalize xValues, yValues, and zValues arrays.
        initialize(
            formObjectArray(xGrid), formObjectArray(yGrid), 
            formObjectArray(zGrid)
        );
}

Builds a regular grid. Maps the non-grid data into the regular grid using an inverse distance between grid and non-grid points. Weighting of distance can be controlled by setting through the power parameter that controls the exponent used on the distance weighting (e.g., distance^power).

 protected double distance(double xDataPt,
    double yDataPt,
    double xGrdPt,
    double yGrdPt) 
{
        double dx = xDataPt - xGrdPt;
        double dy = yDataPt - yGrdPt;
        return Math.sqrt(dx * dx + dy * dy);
}

Calculates the distance between two points.