1 /* Copyright 2002-2019 CS Systèmes d'Information 2 * Licensed to CS Systèmes d'Information (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.utils; 18 19 import org.orekit.propagation.SpacecraftState; 20 21 /** Interface representing a vector function depending on {@link SpacecraftState}. 22 * @see Differentiation#differentiate(StateFunction, int, org.orekit.attitudes.AttitudeProvider, 23 * org.orekit.orbits.OrbitType, org.orekit.orbits.PositionAngle, double, int) 24 * @see StateJacobian 25 * @author Luc Maisonobe 26 * @since 8.0 27 */ 28 public interface StateFunction { 29 30 /** Evaluate the function. 31 * @param state spacecraft state as the sole free parameter of the function. 32 * @return vector value of the function 33 */ 34 double[] value(SpacecraftState state); 35 36 }