Example usage for org.apache.commons.math3.analysis.interpolation BivariateGridInterpolator interpolate

Introduction

In this page you can find the example usage for org.apache.commons.math3.analysis.interpolation BivariateGridInterpolator interpolate.

Prototype

BivariateFunction interpolate(double[] xval, double[] yval, double[][] fval)
        throws NoDataException, DimensionMismatchException;

Source Link

Document

Compute an interpolating function for the dataset.

Usage

From source file:es.uvigo.ei.sing.laimages.core.operations.Interpolator.java

private static double[][] calculateNewValues(double[][] data, int interpolationLevel) {
    final int initialRows = data.length;
    final int initialColumns = data[0].length;

    final BivariateGridInterpolator interpolator = new BilinearInterpolator();
    final BivariateFunction function = interpolator.interpolate(
            IntStream.range(0, initialRows).asDoubleStream().toArray(),
            IntStream.range(0, initialColumns).asDoubleStream().toArray(), data);

    final int newNumRows = CALCULATE_SIZE.applyAsInt(initialRows, interpolationLevel);
    final int newNumColumns = CALCULATE_SIZE.applyAsInt(initialColumns, interpolationLevel);

    final double[][] newValues = new double[newNumRows][newNumColumns];

    final double xFactor = ((double) initialRows - 1d) / ((double) newNumRows - 1d);
    final double yFactor = ((double) initialColumns - 1d) / ((double) newNumColumns - 1d);
    for (int i = 0; i < newValues.length; i++) {
        for (int j = 0; j < newValues[i].length; j++) {
            newValues[i][j] = function.value((double) i * xFactor, (double) j * yFactor);
        }/*from  ww  w  .j  a  v a2s.co m*/
    }

    return newValues;
}

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From source file:com.gordoni.opal.BiInterpolator.java

public BiInterpolator(MapPeriod mp, int what) {
    this.mp = mp;

    Scenario scenario = mp.scenario;//from   w  ww. j  a  v a2 s  .  c  om
    Config config = scenario.config;

    xval = new double[mp.length[0]];
    for (int i = 0; i < xval.length; i++)
        xval[(xval.length - 1) - i] = scenario.scale[0].bucket_to_pf(mp.bottom[0] + i);
    yval = new double[mp.length[1]];
    for (int i = 0; i < yval.length; i++)
        yval[(yval.length - 1) - i] = scenario.scale[1].bucket_to_pf(mp.bottom[1] + i);

    fval = new double[mp.length[0]][mp.length[1]];
    MapPeriodIterator<MapElement> mpitr = mp.iterator();
    while (mpitr.hasNext()) {
        int[] bucket = mpitr.nextIndex().clone();
        MapElement me = mpitr.next();
        int xindex = (xval.length - 1) - (bucket[0] - mp.bottom[0]);
        int yindex = (yval.length - 1) - (bucket[1] - mp.bottom[1]);
        fval[xindex][yindex] = getWhat(me, what);
    }

    BivariateGridInterpolator interpolator;
    if (config.interpolation2.equals("spline"))
        interpolator = new PiecewiseBicubicSplineInterpolator();
    else {
        assert (false);
        return;
    }

    this.f = interpolator.interpolate(xval, yval, fval);
}

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From source file:org.meteoinfo.math.interpolate.InterpUtil.java

/**
 * Make interpolation function for grid data
 * @param x X data/*from www.  j a va2  s . c  o m*/
 * @param y Y data
 * @param z Z data
 * @return Interpolation function
 */
public static BivariateFunction getBiInterpFunc(Array x, Array y, Array z) {
    double[] xd = (double[]) ArrayUtil.copyToNDJavaArray(x);
    double[] yd = (double[]) ArrayUtil.copyToNDJavaArray(y);
    double[][] zd = (double[][]) ArrayUtil.copyToNDJavaArray(z);
    BivariateGridInterpolator li = new BicubicInterpolator();
    BivariateFunction func = li.interpolate(xd, yd, zd);

    return func;
}

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From source file:uk.ac.diamond.scisoft.analysis.dataset.function.Interpolation2D.java

public static Dataset interpolate(IDataset oldx, IDataset oldy, IDataset oldxy, IDataset newx, IDataset newy,
        BivariateGridInterpolator interpolator)
        throws NonMonotonicSequenceException, NumberIsTooSmallException {

    //check shapes
    if (oldx.getRank() != 1)
        throw new IllegalArgumentException("oldx Shape must be 1D");
    if (oldy.getRank() != 1)
        throw new IllegalArgumentException("oldy Shape must be 1D");
    if (oldxy.getRank() != 2)
        throw new IllegalArgumentException("oldxy Shape must be 2D");
    if (oldx.getShape()[0] != oldxy.getShape()[0])
        throw new IllegalArgumentException("oldx Shape must match oldxy Shape[0]");
    if (oldy.getShape()[0] != oldxy.getShape()[1])
        throw new IllegalArgumentException("oldy Shape must match oldxy Shape[1]");
    if (newx.getRank() != 1)
        throw new IllegalArgumentException("newx Shape must be 1D");
    if (newy.getRank() != 1)
        throw new IllegalArgumentException("newx Shape must be 1D");
    if (newy.getSize() != newx.getSize())
        throw new IllegalArgumentException("newx and newy Size must be identical");

    DoubleDataset oldx_dd = (DoubleDataset) DatasetUtils.cast(oldx, Dataset.FLOAT64);
    DoubleDataset oldy_dd = (DoubleDataset) DatasetUtils.cast(oldy, Dataset.FLOAT64);
    DoubleDataset oldxy_dd = (DoubleDataset) DatasetUtils.cast(oldxy, Dataset.FLOAT64);

    //unlike in Interpolation1D, we will not be sorting here, as it just too complicated
    //the user will be responsible for ensuring the arrays are properly sorted

    //oldxy_dd needs to be transformed into a double[][] array
    //this call may throw an exception that needs handling by the calling method
    BivariateFunction func = interpolator.interpolate(oldx_dd.getData(), oldy_dd.getData(),
            convertDoubleDataset2DtoPrimitive(oldxy_dd));

    Dataset rv = DatasetFactory.zeros(new int[] { newx.getSize() }, Dataset.FLOAT64);
    rv.setName(oldxy.getName() + "_interpolated");

    for (int i = 0; i < newx.getSize(); i++) {
        double val = 0.0;
        try {/*  ww w.  j  a v a 2  s.co m*/
            val = func.value(newx.getDouble(i), newy.getDouble(i));
            rv.set(val, i);
        } catch (OutOfRangeException e) {
            rv.set(0.0, i);
        }
    }

    return rv;
}

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