PiecewisePart.java
/* Copyright 2002-2022 CS GROUP
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* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* CS 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,
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* See the License for the specific language governing permissions and
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*/
package org.orekit.forces.gravity.potential;
import org.hipparchus.util.SinCos;
/** Part of a {@link PiecewiseSphericalHarmonics piecewise gravity fields} valid for one time interval.
* @author Luc Maisonobe
* @since 11.1
*/
class PiecewisePart {
/** Converter between (degree, order) indices and flatten array. */
private final Flattener flattener;
/** Components of the spherical harmonics. */
private final TimeDependentHarmonic[] components;
/** Simple constructor.
* @param flattener converter between (degree, order) indices and flatten array
* @param components components of the spherical harmonics
*/
PiecewisePart(final Flattener flattener, final TimeDependentHarmonic[] components) {
this.flattener = flattener;
this.components = components.clone();
}
/** Get the maximum supported degree.
* @return maximal supported degree
*/
public int getMaxDegree() {
return flattener.getDegree();
}
/** Get the maximal supported order.
* @return maximal supported order
*/
public int getMaxOrder() {
return flattener.getOrder();
}
/** Compute the time-dependent part of a spherical harmonic cosine coefficient.
* @param n degree of the coefficient
* @param m order of the coefficient
* @param offsets offsets to reference dates in the gravity field
* @param pulsations angular pulsations in the gravity field
* @return raw coefficient Cnm
*/
public double computeCnm(final int n, final int m,
final double[] offsets, final SinCos[][] pulsations) {
final TimeDependentHarmonic harmonic = components[flattener.index(n, m)];
return harmonic == null ? 0.0 : harmonic.computeCnm(offsets, pulsations);
}
/** Compute the time-dependent part of a spherical harmonic sine coefficient.
* @param n degree of the coefficient
* @param m order of the coefficient
* @param offsets offsets to reference dates in the gravity field
* @param pulsations angular pulsations in the gravity field
* @return raw coefficient Snm
*/
public double computeSnm(final int n, final int m,
final double[] offsets, final SinCos[][] pulsations) {
final TimeDependentHarmonic harmonic = components[flattener.index(n, m)];
return harmonic == null ? 0.0 : harmonic.computeSnm(offsets, pulsations);
}
}