1 /* Copyright 2002-2024 CS GROUP 2 * Licensed to CS GROUP (CS) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * CS licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 package org.orekit.data; 18 19 import java.io.Serializable; 20 21 import org.hipparchus.CalculusFieldElement; 22 import org.orekit.utils.Constants; 23 24 /** 25 * Polynomial nutation function. 26 * 27 * @author Luc Maisonobe 28 * @see PoissonSeries 29 */ 30 public class PolynomialNutation implements Serializable { 31 32 /** Serializable UID. */ 33 private static final long serialVersionUID = 20131007L; 34 35 /** Coefficients of the polynomial part. */ 36 private double[] coefficients; 37 38 /** Build a polynomial from its coefficients. 39 * @param coefficients polynomial coefficients in increasing degree 40 */ 41 public PolynomialNutation(final double... coefficients) { 42 this.coefficients = coefficients.clone(); 43 } 44 45 /** Evaluate the value of the polynomial. 46 * @param tc date offset in Julian centuries 47 * @return value of the polynomial 48 */ 49 public double value(final double tc) { 50 51 double p = 0; 52 for (int i = coefficients.length - 1; i >= 0; --i) { 53 p = p * tc + coefficients[i]; 54 } 55 56 return p; 57 58 } 59 60 /** Evaluate the time derivative of the polynomial. 61 * @param tc date offset in Julian centuries 62 * @return time derivative of the polynomial 63 */ 64 public double derivative(final double tc) { 65 66 double p = 0; 67 for (int i = coefficients.length - 1; i > 0; --i) { 68 p = p * tc + i * coefficients[i]; 69 } 70 71 return p / Constants.JULIAN_CENTURY; 72 73 } 74 75 /** Evaluate the value of the polynomial. 76 * @param tc date offset in Julian centuries 77 * @param <T> type of the filed elements 78 * @return value of the polynomial 79 */ 80 public <T extends CalculusFieldElement<T>> T value(final T tc) { 81 82 T p = tc.getField().getZero(); 83 for (int i = coefficients.length - 1; i >= 0; --i) { 84 p = p.multiply(tc).add(coefficients[i]); 85 } 86 87 return p; 88 89 } 90 91 /** Evaluate the time derivative of the polynomial. 92 * @param tc date offset in Julian centuries 93 * @param <T> type of the filed elements 94 * @return time derivative of the polynomial 95 */ 96 public <T extends CalculusFieldElement<T>> T derivative(final T tc) { 97 98 T p = tc.getField().getZero(); 99 for (int i = coefficients.length - 1; i > 0; --i) { 100 p = p.multiply(tc).add( i * coefficients[i]); 101 } 102 103 return p.divide(Constants.JULIAN_CENTURY); 104 105 } 106 107 }