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Diffstat (limited to 'src/main/java/org/apache/commons/math/analysis/interpolation/MicrosphereInterpolator.java')
-rw-r--r-- | src/main/java/org/apache/commons/math/analysis/interpolation/MicrosphereInterpolator.java | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/src/main/java/org/apache/commons/math/analysis/interpolation/MicrosphereInterpolator.java b/src/main/java/org/apache/commons/math/analysis/interpolation/MicrosphereInterpolator.java new file mode 100644 index 0000000..c2a4009 --- /dev/null +++ b/src/main/java/org/apache/commons/math/analysis/interpolation/MicrosphereInterpolator.java @@ -0,0 +1,118 @@ +/* + * 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 + * + * http://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. + */ +package org.apache.commons.math.analysis.interpolation; + +import org.apache.commons.math.MathException; +import org.apache.commons.math.analysis.MultivariateRealFunction; +import org.apache.commons.math.exception.NotPositiveException; +import org.apache.commons.math.exception.NotStrictlyPositiveException; +import org.apache.commons.math.random.UnitSphereRandomVectorGenerator; + +/** + * Interpolator that implements the algorithm described in + * <em>William Dudziak</em>'s + * <a href="http://www.dudziak.com/microsphere.pdf">MS thesis</a>. + * @since 2.1 + * + * @version $Revision: 980944 $ $Date: 2010-07-30 22:31:11 +0200 (ven. 30 juil. 2010) $ + */ +public class MicrosphereInterpolator + implements MultivariateRealInterpolator { + + /** + * Default number of surface elements that composes the microsphere. + */ + public static final int DEFAULT_MICROSPHERE_ELEMENTS = 2000; + + /** + * Default exponent used the weights calculation. + */ + public static final int DEFAULT_BRIGHTNESS_EXPONENT = 2; + + /** + * Number of surface elements of the microsphere. + */ + private int microsphereElements; + + /** + * Exponent used in the power law that computes the weights of the + * sample data. + */ + private int brightnessExponent; + + /** Create a microsphere interpolator with default settings. + * <p>Calling this constructor is equivalent to call {@link + * #MicrosphereInterpolator(int, int) + * MicrosphereInterpolator(MicrosphereInterpolator.DEFAULT_MICROSPHERE_ELEMENTS, + * MicrosphereInterpolator.DEFAULT_BRIGHTNESS_EXPONENT)}.</p> + */ + public MicrosphereInterpolator() { + this(DEFAULT_MICROSPHERE_ELEMENTS, DEFAULT_BRIGHTNESS_EXPONENT); + } + + /** Create a microsphere interpolator. + * @param microsphereElements number of surface elements of the microsphere. + * @param brightnessExponent exponent used in the power law that computes the + * weights of the sample data. + * @throws NotPositiveException if {@code microsphereElements <= 0} + * or {@code brightnessExponent < 0}. + */ + public MicrosphereInterpolator(final int microsphereElements, + final int brightnessExponent) { + setMicropshereElements(microsphereElements); + setBrightnessExponent(brightnessExponent); + } + + /** + * {@inheritDoc} + */ + public MultivariateRealFunction interpolate(final double[][] xval, + final double[] yval) + throws MathException, IllegalArgumentException { + final UnitSphereRandomVectorGenerator rand + = new UnitSphereRandomVectorGenerator(xval[0].length); + return new MicrosphereInterpolatingFunction(xval, yval, + brightnessExponent, + microsphereElements, + rand); + } + + /** + * Set the brightness exponent. + * @param exponent Exponent for computing the distance dimming + * factor. + * @throws NotPositiveException if {@code exponent < 0}. + */ + public void setBrightnessExponent(final int exponent) { + if (exponent < 0) { + throw new NotPositiveException(exponent); + } + brightnessExponent = exponent; + } + + /** + * Set the number of microsphere elements. + * @param elements Number of surface elements of the microsphere. + * @throws NotStrictlyPositiveException if {@code elements <= 0}. + */ + public void setMicropshereElements(final int elements) { + if (elements <= 0) { + throw new NotStrictlyPositiveException(elements); + } + microsphereElements = elements; + } +} |