PiecewiseBicubicSplineInterpolator.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/*
 * This is not the original file distributed by the Apache Software Foundation
 * It has been modified by the Hipparchus project
 */
package org.hipparchus.analysis.interpolation;

import org.hipparchus.exception.LocalizedCoreFormats;
import org.hipparchus.exception.MathIllegalArgumentException;
import org.hipparchus.exception.NullArgumentException;
import org.hipparchus.util.MathArrays;

/**
 * Generates a piecewise-bicubic interpolating function.
 *
 */
public class PiecewiseBicubicSplineInterpolator
    implements BivariateGridInterpolator {

    /** Empty constructor.
     * <p>
     * This constructor is not strictly necessary, but it prevents spurious
     * javadoc warnings with JDK 18 and later.
     * </p>
     * @since 3.0
     */
    public PiecewiseBicubicSplineInterpolator() { // NOPMD - unnecessary constructor added intentionally to make javadoc happy
        // nothing to do
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public PiecewiseBicubicSplineInterpolatingFunction interpolate( final double[] xval,
                                                                    final double[] yval,
                                                                    final double[][] fval)
        throws MathIllegalArgumentException, NullArgumentException {
        if (xval == null || yval == null || fval == null || fval[0] == null) {
            throw new NullArgumentException();
        }

        if (xval.length == 0 || yval.length == 0 || fval.length == 0) {
            throw new MathIllegalArgumentException(LocalizedCoreFormats.NO_DATA);
        }

        MathArrays.checkOrder(xval);
        MathArrays.checkOrder(yval);

        return new PiecewiseBicubicSplineInterpolatingFunction(xval, yval, fval);
    }

}