InterpolatingMicrosphere2D.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
- *
- * 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.math4.legacy.analysis.interpolation;
- import org.apache.commons.math4.core.jdkmath.JdkMath;
- /**
- * Utility class for the {@link MicrosphereProjectionInterpolator} algorithm.
- * For 2D interpolation, this class constructs the microsphere as a series of
- * evenly spaced facets (rather than generating random normals as in the
- * base implementation).
- *
- * @since 4.0
- */
- public class InterpolatingMicrosphere2D extends InterpolatingMicrosphere {
- /** Space dimension. */
- private static final int DIMENSION = 2;
- /**
- * Create a sphere from vectors regularly sampled around a circle.
- *
- * @param size Number of surface elements of the sphere.
- * @param maxDarkFraction Maximum fraction of the facets that can be dark.
- * If the fraction of "non-illuminated" facets is larger, no estimation
- * of the value will be performed, and the {@code background} value will
- * be returned instead.
- * @param darkThreshold Value of the illumination below which a facet is
- * considered dark.
- * @param background Value returned when the {@code maxDarkFraction}
- * threshold is exceeded.
- * @throws org.apache.commons.math4.legacy.exception.NotStrictlyPositiveException
- * if {@code size <= 0}.
- * @throws org.apache.commons.math4.legacy.exception.NotPositiveException if
- * {@code darkThreshold < 0}.
- * @throws org.apache.commons.math4.legacy.exception.OutOfRangeException if
- * {@code maxDarkFraction} does not belong to the interval {@code [0, 1]}.
- */
- public InterpolatingMicrosphere2D(int size,
- double maxDarkFraction,
- double darkThreshold,
- double background) {
- super(DIMENSION, size, maxDarkFraction, darkThreshold, background);
- // Generate the microsphere normals.
- final double twopi = 2 * Math.PI;
- for (int i = 0; i < size; i++) {
- final double angle = i * twopi / size;
- add(new double[] { JdkMath.cos(angle),
- JdkMath.sin(angle) },
- false);
- }
- }
- /**
- * Copy constructor.
- *
- * @param other Instance to copy.
- */
- protected InterpolatingMicrosphere2D(InterpolatingMicrosphere2D other) {
- super(other);
- }
- /**
- * Perform a copy.
- *
- * @return a copy of this instance.
- */
- @Override
- public InterpolatingMicrosphere2D copy() {
- return new InterpolatingMicrosphere2D(this);
- }
- }